Question #abe90

1 Answer
Apr 9, 2017

1tana[ln|sec(x+a)|ln|secx|]

Explanation:

Using the rule: tan(AB)=tanAtanB1+tanAtanB
Set:
A=x+a
B=x
Substitute these values into the above rule: tan(a)=tan(x+a)(tanx)1+tan(x+a)tanx

The denominator is the antiderivative we want to find.
Note tana is a constant

(1+tan(x+a)tanx)=tan(x+a)(tanx)tana

(1+tan(x+a)tanx)=tan(x+a)(tanx)tana

1tana is a constant that can come out of the integral

1tanatan(x+a)dx - 1tanatanxdx
We use this rule to simplify this furthertanxdx=ln|secx|

1tana[ln|sec(x+a)|ln|secx|]

I did not assume that you meant (1+tanx)(tana+x) which would result in a different answer.