Mathematics

Problem

The first term of an infinite G.P. is the value of

x

satisfying the equation

\log_4(4^x - 15) + x - 2 = 0

and the common ratio is

\cos\left(\frac{2011\pi}{3}\right)

. The sum of G.P. is : (a) 1 (b)

\frac{4}{3}