Question

упростить, тригонометрия

Answer 1

$frac{1+cos alpha -cos^2 frac{ alpha }{2} }{cos^2 frac{ alpha }{2}} = frac{1+2cos^2 frac{ alpha }{2}-1-cos^2 frac{ alpha }{2}}{cos^2 frac{ alpha }{2}} = frac{cos^2 frac{ alpha }{2}}{cos^2 frac{ alpha }{2}} =1$