Please solve the question in the attachment.. .. .. ......... ...

let theta=x

use the formula: tanx/2= (1-cosx)/sinx and sin^2x/x=(1-cosx)/2 and put cosx=y to obtain (y – 1)/[(y+1)(y^3+y^2+y)^0.5]dy

now, this is a really tricky integral and even wolfram alpha is unable to solve this. so the trick to solve it is to multiply the deno and num by (y+1) and then divide the num and denom by y^2 and set y+1/y=z so now you know how it is done :)

note that dz/dy= 1-1/y^2