Math Is Fun Forum

mathminor88

Member

Registered: 2007-09-16

Posts: 12

trig integral

use u = sec x to evaluate

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: trig integral

So use u = secx and evaluate. What’s the problem?

Now integrate!

mathminor88

Member

Registered: 2007-09-16

Posts: 12

Re: trig integral

Sure, it's easy when you know how to do it.

I didn't know to change the tan^2 to it's sec equivalent.
Thanks.

Last edited by mathminor88 (2007-10-01 12:49:32)

bossk171

Member

Registered: 2007-07-16

Posts: 305

Re: trig integral

sin²x + cos²x = 1

Divide through by cos²x

tan²x + 1 = sec²x

Subtract 1 from both sides.

tan²x = sec²x - 1

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There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: trig integral

Sure, it's easy when you know how to do it.

I didn't know to change the tan^2 to it's sec equivalent.
Thanks.

Then you should have stated what it was you found difficult about the problem. That way we know that you’ve tried the problem yourself and aren’t just being lazy. The way you posted your problem here seems to suggest otherwise. (There are people here who would just post their problem without even trying, expecting us to do all the work for them – then they would come back later and copy our solutions as answers to their homework. We don’t want to encourage such bad habits here.)