Final answer:
To simplify the expression (2sin^2a-1)/(sina+cosa), you can use trigonometric identities and properties. First, rewrite sin^2a as (1 - cos^2a) using the Pythagorean identity. Then, simplify the expression further using various trigonometric identities.
Step-by-step explanation:
To simplify the expression (2sin^2a-1)/(sina+cosa), we can use trigonometric identities and properties.
- First, let's rewrite sin^2a as (1 - cos^2a) using the Pythagorean identity.
- Substituting this in the numerator, we have (2(1 - cos^2a) - 1) / (sina + cosa).
- Simplifying further, we get (1 - 2cos^2a) / (sina + cosa).
- Now, we can factor out a negative sign from the numerator to get -2(cos^2a - 1/2) / (sina + cosa).
- Using the identity cos^2a - 1/2 = -sin^2 (pi/2 - a), we can rewrite the expression as -2sin^2(pi/2 - a) / (sina + cosa).
- Finally, we can further simplify the expression as -2sin(pi/2 - a) / (sina + cosa).