Replace x with π/2 - x to get the equivalent integral

but the integrand is even, so this is really just

Substitute x = 1/2 arccot(u/2), which transforms the integral to

There are lots of ways to compute this. What I did was to consider the complex contour integral

where γ is a semicircle in the complex plane with its diameter joining (-R, 0) and (R, 0) on the real axis. A bound for the integral over the arc of the circle is estimated to be

which vanishes as R goes to ∞. Then by the residue theorem, we have in the limit

and it follows that

The answer is 20%
If 50 is your 100%, take 100 and 90 for example it would be obvious that is it 10% off, so with 50 since it is half of 100 you double the 10% which will be 20%. :)
Answer:
3) 10
4) 12
hope that helps buddy
Step-by-step explanation: