Find the derivative and simplify. y = -3xcosx Help!?

1 Answer
Jul 24, 2017

#dy/dx=3xsinx-3cosx#

Explanation:

#"differentiate using the "color(blue)"product rule"#

#"given "y=f(x)g(x)" then"#

#dy/dx=f(x)g'(x)+g(x)f'(x)larr" product rule"#

#f(x)=-3xrArrf'(x)=-3#

#g(x)=cosxrArrg'(x)=-sinx#

#rArrdy/dx=-3x(-sinx)+cosx(-3)#

#color(white)(rArrdy/dx)=3xsinx-3cosx#