Sin(π-a)×cos(3π/2+a)×tg(π/2-a:sin(π/2+a)×ctg(π+a)×cos(π/2-a)

Question

Sin(π-a)×cos(3π/2+a)×tg(π/2-a:sin(π/2+a)×ctg(π+a)×cos(π/2-a)

Comments

tg(n/2-a):sin(n/2+a)?

Answer 1

=sin a*sin a*ctga:cosa*ctg a*sin a=sin acos a:cos a cos a=tg a