Question

Упростите:ctg^2a+sin^2a+ctg^2a*sin^2a

Answer 1

ctg^2a+sin^2a+(ctga*sina)^2=ctg^2a+sin^2a+(cosa/sina*sina)^2=ctg^2a+sin^2a+cos^2a=
ctg^2a+1=1/sin^2a