00:01
For question 42, we're asked to use a substitution to solve this equation.
00:05
So we're given the substitution that y is equal to vx squared.
00:11
So we're going to use this institution basically to replace this, d, y, dx.
00:15
So i'm going to go ahead and differentiate both sides.
00:19
So this means that's d y, dx is equal to vx plus x squared times dvdx, using my product rule.
00:32
And so now i'm going to go ahead and replace this d -y -d -x with this value instead.
00:37
So i get the equation 2vx plus x squared to v -d -x is equal to.
00:47
I'm going to go ahead and use my substitution here.
00:50
So why is equal to vx squared.
00:52
So that means this first term is going to become 2vx, and this term will become cosine of v...