Question

Упростите
cosφ/ cos φ/2+sin φ/2​

Answer 1

$\displaystyle\bf\\\frac{Cos\psi}{Cos\frac{\psi}{2} +Sin\frac{\psi}{2} } =\frac{Cos^{2}\frac{\psi}{2} -Sin^{2} \frac{\psi}{2}}{Cos\frac{\psi}{2}+Sin\frac{\psi}{2}} =\frac{(Cos\frac{\psi}{2} -Sin \frac{\psi}{2})(Cos\frac{\psi}{2} +Sin\frac{\psi}{2} )}{Cos\frac{\psi}{2}+Sin\frac{\psi}{2}} =\\\\\\=Cos\frac{\psi}{2}-Sin\frac{\psi}{2}$