How do you determine the derivative of xcosxxcosx?
1 Answer
Dec 17, 2016
Find the first derivative and then differentiate again.
dy/dx= 1(cosx) + x(-sinx)dydx=1(cosx)+x(−sinx)
dy/dx = cosx - xsinxdydx=cosx−xsinx
Differentiate again.
(d^2y)/(dx^2) = -sinx - (1(sinx) + x(cosx))d2ydx2=−sinx−(1(sinx)+x(cosx))
(d^2y)/(dx^2) = -sinx - sinx - xcosxd2ydx2=−sinx−sinx−xcosx
(d^2y)/(dx^2) = -2sinx - xcosxd2ydx2=−2sinx−xcosx
Hopefully this helps!