What is the derivative of arctan(x-1)arctan(x1)?

1 Answer
Mar 18, 2016

d/dx(arctan(x-1))=1/(x^2+2x+2)ddx(arctan(x1))=1x2+2x+2

Explanation:

We must first know the derivative of arctan(x)arctan(x), which is:

d/dxarctan(x)=1/(1+x^2)ddxarctan(x)=11+x2

According to the chain rule, we see that

d/dxarctan(f(x))=1/(1+(f(x))^2)*f'(x)

So, for arctan(x-1), we see that f(x)=x-1 and f'(x)=1.

d/dxarctan(x-1)=1/(1+(x-1)^2)*1

=1/(1+(x^2-2x+1)

=1/(x^2-2x+2)