ctgx+cosx=1+ctgx*cosx

LS = cotx + cosx

= cosx/sinx + cosx
= (cosx + cos^2x)/sinx

RS = 1 + cotx(cosx)
= 1 + cosx/sinx(cosx)
= 1 + cos^2x/sinx
= (cosx + cos^2x)/sinx
= LS