Mathematics : PU-CET (U.G) 2015 Panjab University Entrance Exam With Answers

Practice Mode:
8.

If sin x + sin$^2$x + sin$^3$x = 1 then cos$^6$x - 4 cos$^4$x + 8 cos$^2$x equals :

A: 1
B: 2
C: 3
D: 4

The answer is: D