What is value of ^2 15^ + ^2 15^ ?

Step-by-step solution

aligned & ^2 15^ + ^2 15^ & = cosec ^2 15^ -1+ ^2 15^ -1 & = cosec ^2 15^ + ^2 15^ -2 aligned aligned & = 1 ^2 15^ + 1 ^2 15^ -2 & = ^2 15^ + ^2 15^ 1 4 (4 ^2 15^ ^2 15^ ) -2 & = 4 ^2 30^ -2= 4 1 4 -2=16-2=14 aligned