Question

ctg(-x/2)=1
помогите плиз

Answer 1

$ctgleft(-frac x2right)=1\-ctgleft(frac x2right)=1\ctgleft(frac x2right)=-1\frac x2=frac{3pi}4+pi k\x=frac{3pi}2+2pi k,;kinmathbb{Z}$