Posted by tom on .
find integral using table of integrals )
integral sin^4xdx
this the formula i used
integral sin^n xdx =1/n sin^n1xcosx +n1/n integral sin^n2
using the formula this is what i got: integral sin^4xdx=1/4sin^3xcosx+3/4 integral sin^2xdx= 1/2sinxcosx+1/2 integral 1 dx
can someone please show me how to combine the two integrals to get the final answer.

calc 
Helper,
My answer, "" = integral symbol
sin^4 x dx =
1/4 sin^3 x cos x + 3/4 (1/2 sin x cos x + 1/2  sin x dx )
1/4 sin^3 x cos x + 3/4 (1/2 sin x cos x + 1/2 (cos x)) + C
1/4 sin^3 x cos x + 3/4 (1/2 sin x cos x  1/2 cos x) + C
1/4 sin^3 x cos x  3/8 sin x cos x
 3/8 cos x + C 
calc 
Helper,
Hold on a few minutes, I might have a mistake.

calc 
Helper,
Mistake fixed below
1/4 sin^3 x cos x + 3/4 (1/2 sin x cos x + 1/2  1 dx )
1/4 sin^3 x cos x + 3/4 (1/2 sin x cos x + 1/2 x) + C
1/4 sin^3 x cos x  3/8 sin x cos x
+ 3/8 x + C