I know the antiderivative of sin is -cos. But what is the antiderivative of -cos? Is it -sin?

It's for this problem (not a test question, just homework):

[IMG]file:///C:/DOCUME%7E1/COMPAQ%7E1/LOCALS%7E1/Temp/moz-screenshot-2.jpg[/IMG]Given

and

and

. Find

?

I got that the first derivative is (-16)(-cos(4x)) -20

but for f(x) i am not sure what the antiderivative of -cosx is.

Thanks!

[IMG]file:///C:/DOCUME%7E1/COMPAQ%7E1/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/COMPAQ%7E1/LOCALS%7E1/Temp/moz-screenshot-1.jpg[/IMG]