Question

Cos квадрат 165-sinквадрат 165​

Answer 1

Ответ:

cos330 = -0,10

Объяснение:

cos(2*165)

cos330

-0.991199

Answer 2

To calculate the value of the expression cos²(165) - sin²(165), we can use trigonometric identities to simplify it.

First, let's recall the Pythagorean identity:

sin²(x) + cos²(x) = 1

Now, we can rewrite the expression using this identity:

cos²(165) - sin²(165) = (1 - sin²(165)) - sin²(165)

Now, we only need to find the value of sin²(165) to proceed.

sin(165) = sin(180 - 15) = sin(180)cos(15) - cos(180)sin(15) = 0 - (-1) * sin(15) = sin(15)

So, sin²(165) = sin²(15).

Now, let's calculate sin²(15):

sin(15) = 0.258819

sin²(15) = 0.258819² = 0.067026361961

Now, we can substitute this back into the original expression:

cos²(165) - sin²(165) = (1 - 0.067026361961) - 0.067026361961 = 0.932973638039

The value of cos²(165) - sin²(165) is approximately 0.93297.