LHS=(1-sinx)/cosx+cosx/(1-sinx)LHS=1−sinxcosx+cosx1−sinx
=(1-sinx)/cosx+(cosx(1+sinx))/((1-sinx)(1+sinx))=1−sinxcosx+cosx(1+sinx)(1−sinx)(1+sinx)
=(1-sinx)/cosx+(cosx(1+sinx))/(1-sin^2x)=1−sinxcosx+cosx(1+sinx)1−sin2x
=(1-sinx)/cosx+(cosx(1+sinx))/cos^2x=1−sinxcosx+cosx(1+sinx)cos2x
=(1-sinx)/cosx+(1+sinx)/cosx=1−sinxcosx+1+sinxcosx
=1/cosx-sinx/cosx+1/cosx+sinx/cosx=1cosx−sinxcosx+1cosx+sinxcosx
=2/cosx=2secx=2cosx=2secx