Answer:

Step-by-step explanation:
Using the product to sum formula
sinxcosy =
[ sin(x + y) + sin(x - y) ] , then
2sinxcosy = sin(x + y) + sin(x - y)
Given
2sin75°cos15° ← with x = 75 and y = 15 , then
= sin(75 + 15) + sin(75 - 15)
= sin90° + sin60°
= 1 + 
= 
Answer:
Rationalize the denominator by multiplying by the conjugate of (1 + √3), namely (1 - √3). this gives us
(1 - √3) / (1 - 3) or (1 - √3) / -2, which can be rewritten as
(-1 + √3)/2, the last answer choice.