Question

if sin alpha is equal to 1 by 2 and Alpha is acute angle then 3 cos alpha minus 4 cos cube Alpha is equal to​

Answer 1

0

Step-by-step explanation:

assuming alpha = A

sinA = 1/2 , given, A < 90°

cosA = √(1 - sin^2A) = √(1 - 1/4) = √3/2

3cosA - 4cos^3 A = 3×√3/2 - 4× (√3/2)^3

= (3√3/2) - (12√3/8) = 0