Question

Cos(-315) Решить по формуле.

Answer 1

cos(-315°)=cos(315°)=cos(360°-45°)=cos45°=√2/2

Answer 2

Ответ:

√2/2.

Объяснение:

сos(-315°) = сos(-360° + 45°) = cos45° = √2/2.

Answer 3

To solve cos(-315) using the formula, we can use the angle addition formula for cosine:

cos(A + B) = cos(A)cos(B) - sin(A)sin(B)

In this case, we can rewrite -315 as -360 + 45:

cos(-315) = cos(-360 + 45)

Using the angle addition formula:

cos(-360 + 45) = cos(-360)cos(45) - sin(-360)sin(45)

Since cos(-360) = cos(0) = 1 and sin(-360) = sin(0) = 0:

cos(-360 + 45) = 1 * cos(45) - 0 * sin(45)

cos(45) is a known value, equal to (√2) / 2:

cos(-360 + 45) = 1 * (√2) / 2 - 0 * sin(45)

cos(-315) = (√2) / 2

Therefore, cos(-315) is equal to (√2) / 2.