Question

Sin squares 5+ sin square 10+ sin square 15+.............+ sin square 85+ sin square 90=19/2

Answer 1

Sinsq5+ sunsq10+.......sinsq45+......+sinsq80+sinsq85+1
sinsqa(90-85)+simag(90-80)+......(1/√2)2+1
=1+1+1+1+1+1+1+1+1/2+1
=19/2