Regarding @1:00 and @2:40 , I wish it was easier to pull these out of my pocket when I needed them. Time to use cue cards to commit more identities to memory.
I think its just a way for him to understand/do integrals with u sub like this easier, at the end of the day he still did the integral correctly. I think it would have been easier for people to understand if he integrated like this: problem: integral of 1/2cos(4x) dx = 1/2 * integral of cos(4x) dx u sub with u=4x = 1/2 * 1/4*sin4x = 1/8 * sin4x but he essentialy did that just in a different way.
Thank you for teaching us more than our college professor could
"this is ging to be equal to... this is going to be equal tooo" :)
I felt he would say it before he said it
Regarding @1:00 and @2:40 , I wish it was easier to pull these out of my pocket when I needed them. Time to use cue cards to commit more identities to memory.
RedPaintedTable See the identity he wrote down at 3:00, in pink? If you distribute the 1/2 over the bracket you get 1/2 + (1/2)cos4x
+Reflective Ducky That's exactly what he did at 3:20
(1/2 × 1) + (1/2 × cos4x) Wesley
+Wesley Richardson Are you blind or what? It is so obvious!
Pls why did u differentiate the 1/2cos4x ?
Because it's an integral
I think its just a way for him to understand/do integrals with u sub like this easier, at the end of the day he still did the integral correctly. I think it would have been easier for people to understand if he integrated like this:
problem:
integral of 1/2cos(4x) dx
= 1/2 * integral of cos(4x) dx
u sub with u=4x
= 1/2 * 1/4*sin4x
= 1/8 * sin4x
but he essentialy did that just in a different way.
its confusing me more
love your vids but this was very confusing and unclear to me ! maybe it was just a difficult problem
Please sir videos post with this Technic is not clearly visible.
not double angle, half angle. 2:00
You can still use the double angle formula in order to derive cos^2(x) and sin^2(x). So he's correct.
@@djSquire1 yup
omg, why r u doing comlicated business all of this???
Should the 1/8(sin4x) be negative? Integ. of cosx = -sinx?
i was thinking the same thing
integral of cosx is sinx
yeah ! right ??!!
Integral of cos is sin. You're confusing the derivative of cos which indeed is -sin
????????
dont know what just happened
Buzz Lightyear?
Tf!!you really messed me up