Answer:
(2sin a - 1)(2sin a + 1)
Step-by-step explanation:
Here, we want to express what is given as a product
Mathematically;
cos2a = 1-2sin^2A
So we have;
1-2(1-2sin^a)
= 1 - 2 + 4sin^2a
= 4sin^2a - 1
Using the difference of two squares, this is;
(2sin(a) - 1)(2sin a + 1)