Question

(tg(180-a) sin(90-a)) /cos(270+a)=СРОЧНО!!!!!

Answer 1

Используем формулы приведения и получим:

(-tg a *cos a)/sin a=-1

Answer 2

To simplify the given expression, we'll use trigonometric identities. Let's break it down step by step:

1. Recall the following trigonometric identities:

   • sin(180° - a) = sin(a)
   • sin(90° - a) = cos(a)
   • cos(270° + a) = -sin(a)

2. Substitute these identities into the given expression:

   (tg(180° - a) * sin(90° - a)) / cos(270° + a)

   becomes

   (tan(a) * cos(a)) / -sin(a)

3. Now, simplify further by canceling out common factors:

   = -(tan(a) * cos(a) / sin(a))

4. Recall the trigonometric identity: tan(a) = sin(a) / cos(a)

5. Substitute tan(a) in terms of sin(a) and cos(a):

   = -((sin(a) / cos(a)) * cos(a) / sin(a))

6. The sin(a) in the numerator and denominator cancels out:

   = -1

So, the simplified expression is -1.