IMPORTANT NOTE: At 5:35 the author misses out a 'y' - it should read v=y+3xy^2 NOT v=y+3x^2 - however all of the maths following it is correct. For more videos on the chain rule see our playlist 'Chain Rule' at ua-cam.com/play/PLlX3COjsHPVBhyHwVmKS7RYCS0SqHULST.html.
IMPORTANT NOTE: At 5:35 the author misses out a 'y' - it should read v=y+3xy^2 NOT v=y+3x^2 - however all of the maths following it is correct. For more videos on the chain rule see our playlist 'Chain Rule' at ua-cam.com/play/PLlX3COjsHPVBhyHwVmKS7RYCS0SqHULST.html.