Question

Cos2a/sina cosa -sin2a​

Answer 1

Объяснение:

вот решение на картинке

Answer 2

To simplify the expression (cos(2a) / sin(a) * cos(a) - sin(2a)), we can use trigonometric identities to make it more manageable.

First, let's rewrite cos(2a) and sin(2a) using trigonometric identities:

1. cos(2a) = cos^2(a) - sin^2(a)
2. sin(2a) = 2sin(a)cos(a)

Now, we can substitute these identities into the expression:

(cos^2(a) - sin^2(a)) / (sin(a)cos(a)) - 2sin(a)cos(a)

Next, we can factor the common term sin(a)cos(a) from the numerator:

(sin(a)cos(a)(cos^2(a)/sin(a)cos(a) - sin^2(a)/sin(a)cos(a))) - 2sin(a)cos(a)

Now, we simplify each term separately:

1. cos^2(a)/sin(a)cos(a) = (cos(a)/sin(a)) * cos(a) = cot(a) * cos(a)
2. sin^2(a)/sin(a)cos(a) = (sin(a)/sin(a)) * (cos(a)/cos(a)) = 1

So, our expression becomes:

(sin(a)cos(a)(cot(a) - 1)) - 2sin(a)cos(a)

Now, we can factor out sin(a)cos(a) from both terms:

sin(a)cos(a)(cot(a) - 1 - 2)

Now, simplify further:

sin(a)cos(a)(cot(a) - 3)

So, the simplified expression is sin(a)cos(a)(cot(a) - 3).