We have:
(sinx-sinxcosx)/(sinx+sinxtanx)=(1-cosx)/(1+tanx)sinx−sinxcosxsinx+sinxtanx=1−cosx1+tanx
I'm first going to factor out sinxsinx in the numerator and denominator on the left side:
(sinx(1-cosx))/(sinx(1+tanx))=(1-cosx)/(1+tanx)sinx(1−cosx)sinx(1+tanx)=1−cosx1+tanx
which I can write as:
(sinx/sinx)(1-cosx)/(1+tanx)=(1-cosx)/(1+tanx)(sinxsinx)1−cosx1+tanx=1−cosx1+tanx
(1)(1-cosx)/(1+tanx)=(1-cosx)/(1+tanx)(1)1−cosx1+tanx=1−cosx1+tanx
(1-cosx)/(1+tanx)=(1-cosx)/(1+tanx)color(white)(000)color(green)sqrt1−cosx1+tanx=1−cosx1+tanx000√