Saturday

November 22, 2014

November 22, 2014

Posted by **Vicky** on Thursday, September 20, 2012 at 1:42am.

I found the table: ∫cos^n u du = (1/n)cos^(n-1)u sinu + (n-1/n)∫sin^(n-2)u du = 1/4 cos^(4-1)u sinu + (4-1/4)∫sin^(4-2) u du

so what i did the problem: let u=3x then du=3dx

=1/4*1/3 cos^3u sinu + 3/4*1/3 ∫sin^2 u du.

=1/12 cos^3u sinu + 1/4 -cos^2 u +c..

so am i doing right step??

- Calculus AP -
**Steve**, Thursday, September 20, 2012 at 11:37am∫sin^2 u du is not just -cos^2 u

sin^2(u) = (cos(2u)-1)/2

so

∫sin^2 u du = 1/4 sin(2u) - u/2

visit wolframalpha.com and enter

integral cos^4 3x dx

and then click the "show steps" button

**Answer this Question**

**Related Questions**

calculus II - ∫ tan^2 x sec^3 x dx If the power of the secant n is odd, ...

Math integrals - What is the indefinite integral of ∫ [sin (π/x)]/ x^...

Integration? - Sorry, i have a load of questions on integration... thanks for ...

Calculus AP - hi again im really need help TextBook: James Stewart:Essential ...

tigonometry - expres the following as sums and differences of sines or cosines ...

calculus - Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x...

trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...

Math - Calculus - The identity below is significant because it relates 3 ...

TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...

Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...