Repeated application of intergration by parts gives us, the reduction formula if the integrand is dependent on a natural number n.
If `int(cos^(m)x)/(sin^(n)x)dx=(cos^(m-1)x)/((1-n)sin^(n-1)x)+A int (cos^(m-2)x)/(sin^(n-2)x)dx+c`, then A is equal to-
A. `(m)/(m+n)`
B. `(m-1)/(m+n)`
C. `(m)/(m+n-1)`
D. `(m-1)/(m-n)`
