How do you differentiate f(x)=sinx/(1-cosx)f(x)=sinx1cosx?

1 Answer
Oct 5, 2016

(df)/(dx)=-1/(1-cosx)dfdx=11cosx

Explanation:

We use the quotient formula here. It states if f(x)=(g(x))/(h(x))f(x)=g(x)h(x)

then (df)/(dx)=((dg)/(dx)xxh(x)-(dh)/(dx)xxg(x))/(h(x))^2dfdx=dgdx×h(x)dhdx×g(x)(h(x))2

As f(x)=sinx/(1-cosx)f(x)=sinx1cosx

(df)/(dx)=(cosx xx(1-cosx)-sinx xxsinx)/(1-cosx)^2dfdx=cosx×(1cosx)sinx×sinx(1cosx)2

= (cosx-cos^2x-sin^2x)/(1-cosx)^2cosxcos2xsin2x(1cosx)2

= (cosx-(cos^2x+sin^2x))/(1-cosx)^2cosx(cos2x+sin2x)(1cosx)2

= (cosx-1)/(1-cosx)^2cosx1(1cosx)2

= -(1-cosx)/(1-cosx)^21cosx(1cosx)2

= -1/(1-cosx)11cosx