What is the derivative of this function (cos x) / (1-sinx)?

1 Answer
Oct 22, 2017

secx(secx+tanx).

Explanation:

Let, y=cosx/(1-sinx).

:. y=cosx/(1-sinx)xx(1+sinx)/(1+sinx),

=(cosx(1+sinx))/(1-sin^2x)=(cosx(1+sinx))/cos^2x.

:. y=(1+sinx)/cosx=1/cosx+sinx/cosx, i.e.,

y=secx+tanx.

rArr dy/dx=secxtanx+sec^2x=secx(tanx+secx).