How do you find the derivative of #f(x)=pitan(pir^2-5r)#?

1 Answer
May 1, 2017

#(2\pi^2x-5\pi)sec^2(\pi x^2-5x)#

Explanation:

Assuming you meant #f(x)=\pi tan(\pi x^2-5x)#

#\pi# is a constant so we can ignore that. Since the inside of tangent is a function we have to use the chain rule. The derivative of #tan(x)# is #sec^2(x)# so we do get the following.
#\frac{d}{dx}f(x)=\pi sec^2(\pi x^2-5x)(\frac{d}{dx}g(x))#

Then we multiply the derivative of everything inside the parentheses which is
#\frac{d}{dx}g(x)=2\pir-5#

Combining them we get
#\frac{d}{dx}f(x)=\pi sec^2(\pi x^2-5x)(2\pix-5)=(2\pi^2x-5\pi)sec^2(\pi x^2-5x)#

You can expand it, but it might not look as clean.