evaluate the derivative of f(X)= 3Xsin(X) at a=0

Answer 1

is that at a=0 or x=0,,
anyway, to get the derivative, do the chain rule since two different terms with x are multiplied,, to do this let g(x)=3x and h(x)=sin x
thus d/dx [g(x)h(x)] = g(x)*h'(x) + g'(x)h(x)
*g(x)*h'(x) = you get derivative of h(x)=sin x an multiply this to g(x)=3x
*g'(x)h(x) = you get derivative of g(x)=3x an multiply this to h(x)=sin x

so there,, please ask questions if you did not understand~

Answer 2

I'm not too sure if it's a=0 or x=0... becuase my worksheet said a=0. Anyways after i use the rule, would I need to plug in the zero?