What is the antiderivative of 1/ (1+sinx) dx11+sinxdx?

1 Answer
May 8, 2018

I=tanx-secx+cI=tanxsecx+c

Explanation:

We know that,
color(red)((1)sin^2theta+ cos^2theta=1(1)sin2θ+cos2θ=1
color(blue)((2)1/costheta=sectheta and sintheta/costheta=tantheta(2)1cosθ=secθandsinθcosθ=tanθ
color(violet)((3)intsec^2xdx=tanx+c(3)sec2xdx=tanx+c
color(violet)((4)intsecxtanxdx=secx+c(4)secxtanxdx=secx+c
Here,

I=int1/(1+sinx)dx=int((1-sinx))/((1+sinx)(1-sinx))dxI=11+sinxdx=(1sinx)(1+sinx)(1sinx)dx

=>I=int(1-sinx)/(1-sin^2x)dxI=1sinx1sin2xdx

=int(1-sinx)/cos^2xdx...tocolor(red)(Apply(1)

=int[1/cos^2x-sinx/cos^2x]dx

=int[sec^2x-secxtanx]dx...tocolor(blue)(Apply(2)

Using , color(violet)((3) and (4), we get

I=tanx-secx+c