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Fri 11 Mar, 2005 06:26 pm
Hi can someone help me with this integral?
It's the integral of cos ^ 4 (x) dx
Don't integrals require a lowe and upper boundary?
Indefinite integrals don't
2 standard integrals are:
Integrate cos ^ 2 (x) dx = 1/2x + 1/4sin2x + Constant
and
Integrate cos ^ n (x) dx = 1/n cos ^(n-1) x sin x + (n-1)/n * Integrate cos ^ (n-2) x dx
So combine these chain itegrations to get
Integrate cos ^ 4(x)dx = 1/4 cos ^(3) x sin x + 3/4 [1/2x + 1/4sin2x + Constant]