Question

Докажите тождества tgx+ctgx=2/sin2x

Answer 1

$frac{sinx}{cosx} + frac{cosx}{sinx} = frac{sin^2x+cos^2x}{sinx*cosx} = frac{1}{sinxcosx} = frac{2}{2sinx*cosx} = frac{2}{sin2x}$