What is the integral of int tan^5(x)*sec^4(x)dxtan5(x)sec4(x)dx?

1 Answer
Jul 5, 2016

= 1/8tan^8(x) + 1/6tan^6(x) + C=18tan8(x)+16tan6(x)+C

Explanation:

int dx qquad tan^5(x)*sec^4(x)

= int dx qquad tan^5(x)*color{red}{sec^2(x)}*sec^2(x)

using well known identity....
= int dx qquad tan^5(x)*color{red}{(tan^2(x) + 1)}*sec^2(x)

= int dx qquad (tan^7(x) + tan^5(x))*sec^2(x)

= int dx qquad tan^7(x)*sec^2(x) + tan^5(x)*sec^2(x)

= 1/8tan^8(x) + 1/6tan^6(x) + C