Given y=f(u) and u=g(x)
find (dy/dx)=f'(g(x))g'(x)
y=u^2 ; u=4x5
My homework was going just fine until I got to this question. I'm not sure I even know what it's asking. Any ideas?
Here's an image of the question with it's possible answers if that helps: http://i.imgur.com/1nq0I.jpg
Any help would really be appreciated. Thanks. :)
find (dy/dx)=f'(g(x))g'(x)
y=u^2 ; u=4x5
My homework was going just fine until I got to this question. I'm not sure I even know what it's asking. Any ideas?
Here's an image of the question with it's possible answers if that helps: http://i.imgur.com/1nq0I.jpg
Any help would really be appreciated. Thanks. :)

dy/dx = dy/du * du/dx
y = u^2 => dy/du = 2u
u = 4x  5 => du/dx = 4
dy/dx = 2u * 4 = 8u
=8 *(4x  5)
=32x  40
Ans. B
y = u^2 => dy/du = 2u
u = 4x  5 => du/dx = 4
dy/dx = 2u * 4 = 8u
=8 *(4x  5)
=32x  40
Ans. B

y ' = 2(4x5)(4)=8(4x5)