Question

Cos2 a/Cos a -sin a = ?

Answer 1

Надо было упростить или сократить.

Answer 2

Для начала, я предполагаю, что вы хотели задать вопрос на английском языке. Если вы хотите задать вопрос на русском языке, пожалуйста, сформулируйте его еще раз, чтобы я мог вам помочь.

Now, let's address your question in English. The expression you provided is:

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

To simplify this expression, we can use trigonometric identities. One of the most commonly used identities is:

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

Substituting this identity into the expression, we get:

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

Next, we can simplify further by combining the fractions:

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

Now, let's expand the expression:

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

We can simplify this expression by factoring out a common term:

(1 - sin(a) * (sin(a) + cos(a))) / cos(a)

And that is the simplified expression for cos^2(a) / cos(a) - sin(a).

It's worth mentioning that depending on the context or specific values of 'a', this expression can be further simplified or evaluated numerically.