Question #16a73

1 Answer
Sep 28, 2017

...I'm going to interpret the function as

#y = (cos(x))^3#

...so the derivative in this case can be found via the chain rule:

if #y = u(v(x))# then #(dy)/dx = (du)/(dv) (dv)/dx#

and in this case #u(v) = v^3#, and #v(x) = cos(x)#

so #(du)/(dv) = 3v^2 = 3(cos(x)^2)#, and #(dv)/dx = -sin(x)#

put these all together:

#(dy)/dx = (3cos^2x)(-sinx)#

GOOD LUCK!