Question

1)Используя формулы привидения вычислить: sin 315 градусов2)Определить знак функции cos 1105 градусов Помогите пожалуйста!

Answer 1

Вот на фото. ответи: -√2/2; положителен

Answer 2

Calculating sin 315 degrees using angle reduction formula

To calculate sin 315 degrees, we can use the angle reduction formula for sine. The angle reduction formula states that sin (360 - θ) = sin θ, where θ is the given angle.

In this case, we have sin 315 degrees. Since 315 degrees is greater than 360 degrees, we can use the angle reduction formula to find an equivalent angle within the range of 0 to 360 degrees.

To find an equivalent angle within the range of 0 to 360 degrees, we can subtract 360 degrees from 315 degrees until we get an angle within the desired range.

315 degrees - 360 degrees = -45 degrees

Now we have an equivalent angle of -45 degrees within the range of 0 to 360 degrees. We can use the angle reduction formula again to find the value of sin -45 degrees.

sin (-45 degrees) = sin (360 degrees - 45 degrees) = sin 315 degrees

Using the angle reduction formula, we have reduced the angle to an equivalent angle within the range of 0 to 360 degrees. Now we can calculate the value of sin 315 degrees.

The value of sin 315 degrees is -0.7071.