Question

Упростите
$\frac{sina}{2sin^2 \frac{a}{2} }$

Answer 1

sin2(π8+A2)−sin2(π8−A2)

=sin(π8+A2+π8−A2)×sin(π8+A2−π8+A2)

=sin(π4)×sin(A)=1√2sinA