Hi all, I am stuck on this trig integral problem. The answer is provided in the book, but I do not know how to get it. The problem is this:(adsbygoogle = window.adsbygoogle || []).push({});

Integral of (secX)^3 dx

it says first use integration by parts:

u = sec x du = sec x tan x dx

dv = (secx)^2 dx v = tan x

uv - integral (v du) = sex x tan x - integral sec x((secx)^2-1) dx

Then it says secx tanx - integral (sec x)^3 dx + integral sec x dx

Now there is another (sec x)^3 like in the original problem, after this step they just provide the answer, but how ?

The answer is 1/2(secxtanx + ln |secx+tanx|) + C

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# Homework Help: Calculus Problem Help Integral of (secx)^3 dx

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