▲ 172 ▼ The SAT Question Everyone Got Wrong (www.youtube.com) submitted 2 years ago by simple@lemm.ee to c/videos@lemmy.world 50 comments fedilink hide all child comments
[–] NocturnalMorning@lemmy.world 6 points 2 years ago (2 children) Watch the video, it's explained. permalink fedilink source parent hideshow 4 child comments replies: [+] ___f____g___@lemmy.ca 2 points 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent [–] SpaceNoodle@lemmy.world -1 points 2 years ago (2 children) This should have been an article. What's the summary? permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 1 point 2 years ago (1 child) I summarized it above, there's an extra rotation included when the outer circle moves along the inner circle, essentially falling a bit with every roll forward. If the outer circle rolled along a straight line of the same length as the circumference of the inner circle, it would only roll 3 times, but moving around the circle instead adds exactly one extra rotation. That other gent says this is used in calculating orbits too, where you're also moving forward while constantly falling permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 2 points 2 years ago (1 child) I read an article about it. Everybody is doing a shit job of describing what happens. The outer circle naturally makes a full rotation as it travels around the inner one, as the path it follows goes around a full 360°, so that counts as one of the rotations it ends up making, which is in addition to the 3 due to travel around the circumference. permalink fedilink source parent hideshow 2 child comments replies: [–] OmnislashIsACloudApp@lemmy.world 2 points 2 years ago (1 child) thank you, that was the comment that explained it for me permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) Add the radius together. If the circle is inside. B-A 3-1 = 2. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 1 point 2 years ago (1 child) Does not compute permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) It’s in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5 rotations. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent [–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent [+] SpaceNoodle@lemmy.world -1 points 2 years ago (1 child) [removed by mod] permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world 0 points 2 years ago (1 child) …? permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[+] ___f____g___@lemmy.ca 2 points 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent
[–] SpaceNoodle@lemmy.world -1 points 2 years ago (2 children) This should have been an article. What's the summary? permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 1 point 2 years ago (1 child) I summarized it above, there's an extra rotation included when the outer circle moves along the inner circle, essentially falling a bit with every roll forward. If the outer circle rolled along a straight line of the same length as the circumference of the inner circle, it would only roll 3 times, but moving around the circle instead adds exactly one extra rotation. That other gent says this is used in calculating orbits too, where you're also moving forward while constantly falling permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 2 points 2 years ago (1 child) I read an article about it. Everybody is doing a shit job of describing what happens. The outer circle naturally makes a full rotation as it travels around the inner one, as the path it follows goes around a full 360°, so that counts as one of the rotations it ends up making, which is in addition to the 3 due to travel around the circumference. permalink fedilink source parent hideshow 2 child comments replies: [–] OmnislashIsACloudApp@lemmy.world 2 points 2 years ago (1 child) thank you, that was the comment that explained it for me permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) Add the radius together. If the circle is inside. B-A 3-1 = 2. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 1 point 2 years ago (1 child) Does not compute permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) It’s in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5 rotations. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent [–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent [+] SpaceNoodle@lemmy.world -1 points 2 years ago (1 child) [removed by mod] permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world 0 points 2 years ago (1 child) …? permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] protist@mander.xyz 1 point 2 years ago (1 child) I summarized it above, there's an extra rotation included when the outer circle moves along the inner circle, essentially falling a bit with every roll forward. If the outer circle rolled along a straight line of the same length as the circumference of the inner circle, it would only roll 3 times, but moving around the circle instead adds exactly one extra rotation. That other gent says this is used in calculating orbits too, where you're also moving forward while constantly falling permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 2 points 2 years ago (1 child) I read an article about it. Everybody is doing a shit job of describing what happens. The outer circle naturally makes a full rotation as it travels around the inner one, as the path it follows goes around a full 360°, so that counts as one of the rotations it ends up making, which is in addition to the 3 due to travel around the circumference. permalink fedilink source parent hideshow 2 child comments replies: [–] OmnislashIsACloudApp@lemmy.world 2 points 2 years ago (1 child) thank you, that was the comment that explained it for me permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent
[–] SpaceNoodle@lemmy.world 2 points 2 years ago (1 child) I read an article about it. Everybody is doing a shit job of describing what happens. The outer circle naturally makes a full rotation as it travels around the inner one, as the path it follows goes around a full 360°, so that counts as one of the rotations it ends up making, which is in addition to the 3 due to travel around the circumference. permalink fedilink source parent hideshow 2 child comments replies: [–] OmnislashIsACloudApp@lemmy.world 2 points 2 years ago (1 child) thank you, that was the comment that explained it for me permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent
[–] OmnislashIsACloudApp@lemmy.world 2 points 2 years ago (1 child) thank you, that was the comment that explained it for me permalink fedilink source parent hideshow 2 child comments replies: [–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent
[–] SpaceNoodle@lemmy.world 1 point 2 years ago Thanks for letting me know! It was too frustrating to not share. permalink fedilink source parent
[–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) Add the radius together. If the circle is inside. B-A 3-1 = 2. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 1 point 2 years ago (1 child) Does not compute permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) It’s in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5 rotations. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent [–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent [+] SpaceNoodle@lemmy.world -1 points 2 years ago (1 child) [removed by mod] permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world 0 points 2 years ago (1 child) …? permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] protist@mander.xyz 1 point 2 years ago (1 child) Does not compute permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) It’s in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5 rotations. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent [–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent
[–] schmidtster@lemmy.world -2 points 2 years ago* (2 children) It’s in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5 rotations. permalink fedilink source parent hideshow 4 child comments replies: [–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent [–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent
[–] protist@mander.xyz 4 points 2 years ago First you said add the radii together, then you gave an example subtracting them, but either way this is incorrect. You divide the larger radius by the smaller radius and add 1 permalink fedilink source parent
[–] uphillbothways@kbin.social 1 point 2 years ago* Not quite. With radius 2 and 3 circles, the outer circle would take 2.5 rotations to complete the revolution. You have to set the first circle radius to 1 (divide both radii by the lesser) and then add the radii to calculate the relative circumference of the circle drawn by the motion of the center of the outer circle, so the answer would be calculated like: 2/2 + 3/2 = 5/2 = 2.5 permalink fedilink source parent
[+] SpaceNoodle@lemmy.world -1 points 2 years ago (1 child) [removed by mod] permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world 0 points 2 years ago (1 child) …? permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] schmidtster@lemmy.world 0 points 2 years ago (1 child) …? permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] bisby@lemmy.world 1 point 2 years ago* (last edited 2 years ago) (1 child) Its not even remotely what you said. Its A/B+1 or A/B-1 for an interior loop. edit: I didn't need to be this aggressive. It's VAGUELY what you said. its (A+B)/B. You have missed the /B part.. which is A/B + 1. in the example you gave, for radius 2 and 3... it would be 3/2 + 1 or 2.5. Not 5 (off by a factor of 2 because /B) permalink fedilink source parent hideshow 2 child comments replies: [–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] schmidtster@lemmy.world -3 points 2 years ago (1 child) They explain multiple ways to do it in the video. A circle with a radius of 2 and a circle with a radius of 3 would be 5. permalink fedilink source parent hideshow 2 child comments replies: [–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent
[–] bisby@lemmy.world 3 points 2 years ago No they don't N is the ratio of the circles and its just +1 or -1 depending on outer or inner. permalink fedilink source parent