# Question: 10 sum the following infinite series a sin2x 12sin22x...

###### Question details

10. Sum the following infinite series:

a) sin^{2}x + (1/2)sin^{2}2x +
(1/2^{2})sin^{2}2^{2}x + ...

b) cos^{2}x - (1/2)cos^{2}2x +
(1/2^{2})cos^{2}2^{2} + ...