To simplify this expression, we can use the trigonometric identity:
cos(3a) = 4cos^3(a) - 3cos(a)
Therefore, the expression becomes:
(4cos^3(a) - 3cos(a) - cos(a)) / (4cos^3(a) - 3cos(a) + cos(a))
Now, we can combine like terms:
(4cos^3(a) - 4cos(a)) / (4cos^3(a) - 2cos(a))
Factor out a 4 from the numerator:
4(cos^3(a) - cos(a)) / (4cos^3(a) - 2cos(a))
Factor out a cos(a) from the denominator:
4(cos^3(a) - cos(a)) / (cos(a)(4cos^2(a) - 2))
Simplify by canceling out common terms:
4(cos^2(a) - 1) / (2cos^2(a) - 1)
Therefore, the simplified expression is:
To simplify this expression, we can use the trigonometric identity:
cos(3a) = 4cos^3(a) - 3cos(a)
Therefore, the expression becomes:
(4cos^3(a) - 3cos(a) - cos(a)) / (4cos^3(a) - 3cos(a) + cos(a))
Now, we can combine like terms:
(4cos^3(a) - 4cos(a)) / (4cos^3(a) - 2cos(a))
Factor out a 4 from the numerator:
4(cos^3(a) - cos(a)) / (4cos^3(a) - 2cos(a))
Factor out a cos(a) from the denominator:
4(cos^3(a) - cos(a)) / (cos(a)(4cos^2(a) - 2))
Simplify by canceling out common terms:
4(cos^2(a) - 1) / (2cos^2(a) - 1)
Therefore, the simplified expression is:
4(cos^2(a) - 1) / (2cos^2(a) - 1)