Ctg(270-a)/1-tg^2(a-180)*ctg^2(360-a)-1/ctg(180+a)

Question

Ctg(270-a)/1-tg^2(a-180)*ctg^2(360-a)-1/ctg(180+a)

Answer 1

ctg(270-a)/1-tg^2(a-180)ctg^2(360-a)-1/ctg(180+a)=

=-tga/1+tg^2a*ctg^2a-1/ctga=

=-tga/tga*ctga*(1+ctga*tga)-1/ctga=

=-1/2ctga-1/ctga=

=(-1-2)/2ctga=

=-3/2ctga=

=-1,5tga