Question

Solve:
[1/(sin 45 sin 46)] + [1/(sin 47 sin 48)] + ........................+ [1(sin 133 sin 134)]

Answer 1

the general term of the series is 

t(n)  =  1/ sin xsin ( x+1)

Now expand sin (x + 1) using sin (a + B), simplify, and you will get around 57.14

Hope this helps