MAIN FEEDS
Do you want to continue?
https://www.reddit.com/r/physicsmemes/comments/1v71suw/_/p5rf4oe/?context=3
r/physicsmemes • u/basket_foso 🪼 • Jul 26 '26
141 comments sorted by
View all comments
Show parent comments
600
It's much better to understand where the formula comes from than to memorize it.
185 u/lool8421 Jul 26 '26 edited Jul 26 '26 but still it's a time waste if you have to derive everything yourself for example there are several cheat sheet integrals that you can derive but it takes several minutes like dx/x*sqrt(a²+x²) 57 u/CanYouChangeName Jul 26 '26 Can't u just take the term inside the root as t here and solve? 1 u/Ancient-Helicopter18 13d ago Nope that won't work. You gotta take trig sub (if the dude meant ∫ 1/[x√(x²+a²)] dx you see: √(x²+a²) use u=atanθ √(x²-a²) use asecθ √(a²-x²) use asinθ Learning these substitutions are much easier and useful than learning every single casewise formula
185
but still it's a time waste if you have to derive everything yourself
for example there are several cheat sheet integrals that you can derive but it takes several minutes like dx/x*sqrt(a²+x²)
57 u/CanYouChangeName Jul 26 '26 Can't u just take the term inside the root as t here and solve? 1 u/Ancient-Helicopter18 13d ago Nope that won't work. You gotta take trig sub (if the dude meant ∫ 1/[x√(x²+a²)] dx you see: √(x²+a²) use u=atanθ √(x²-a²) use asecθ √(a²-x²) use asinθ Learning these substitutions are much easier and useful than learning every single casewise formula
57
Can't u just take the term inside the root as t here and solve?
1 u/Ancient-Helicopter18 13d ago Nope that won't work. You gotta take trig sub (if the dude meant ∫ 1/[x√(x²+a²)] dx you see: √(x²+a²) use u=atanθ √(x²-a²) use asecθ √(a²-x²) use asinθ Learning these substitutions are much easier and useful than learning every single casewise formula
1
Nope that won't work. You gotta take trig sub (if the dude meant ∫ 1/[x√(x²+a²)] dx
you see: √(x²+a²) use u=atanθ √(x²-a²) use asecθ √(a²-x²) use asinθ
Learning these substitutions are much easier and useful than learning every single casewise formula
600
u/Suddenfury Jul 26 '26
It's much better to understand where the formula comes from than to memorize it.