Posted by **Andrea** on Wednesday, March 4, 2009 at 6:33pm.

How would you integrate tan5xdx ?

Thanks in advance.

Can you use u substitution?

- calculus -
**Reiny**, Wednesday, March 4, 2009 at 6:39pm
try taking the derivative of

ln(cosx)

that should give you a good hint

- calculus -
**Andrea**, Wednesday, March 4, 2009 at 7:33pm
I know you get -sin x; I know how to do the problem without the 5, but I don't understand how to do the problem since it is tangent of 5x

- calculus -
**drwls**, Wednesday, March 4, 2009 at 10:06pm
The derivative of ln(cosx) is actually

-tanx, not -sinx. "ln" means "natural (base e) logarithm of..

For the integral of tan 5x, let u = 5x

tan 5x = u

du = 5 dx

integral of tan(5x) dx

= integral of (1/5) tan u du

= -(1/5)ln cos u

= -(1/5)ln cos(5x)

## Answer This Question

## Related Questions

- calculus-integration! - should i use substitution?? if yes how should should i ...
- Calculus - Integrate (1/2)sin(x^(1/2))dx. I've tried using u-substitution, with ...
- calculus - integrate 3/25+4x^3....use 2x=5tanΦ as a substitution
- Calculus - Integrate [1/square root of(e^(2x)-1)]. I have to use u substitution...
- [Calculus] U-substitution for Integrals - Integrate from 1 to 5 of (3x-5)^5 dx...
- calculus help please - dy/dx = 2y^2 Integrating...y=2/3 y^3 + C put 1,-1 into ...
- Integral calculus - Please do help solve the followings 1) Integrate e^4 dx 2) ...
- calculus - We're doing indefinite integrals using the substitution rule right ...
- Calculus - How to integrate dx/(4-5 sin x) using t-substitution method(i.e. ...
- Calculus - Can someone help me to integrate by substitution the indefinite ...

More Related Questions