Question

Чему равен сos(3пи+а)?

Answer 1

Ответ: -cos(a)

cos(3$\pi$+a)= cos($\pi$+a)= -cos(a)

Answer 2

Calculation of cos(3π + a)

To calculate the value of cos(3π + a), we can use the trigonometric identity:

cos(α + β) = cos(α)cos(β) - sin(α)sin(β)

In this case, α = 3π and β = a. Substituting these values into the identity, we get:

cos(3π + a) = cos(3π)cos(a) - sin(3π)sin(a)

Now, let's evaluate the values of cos(3π) and sin(3π):

According to the unit circle, the cosine of 3π is equal to -1, and the sine of 3π is equal to 0.

Substituting these values into the equation, we have:

cos(3π + a) = -1 * cos(a) - 0 * sin(a) = -cos(a)

Therefore, the value of cos(3π + a) is equal to -cos(a).

Please note that this calculation assumes that 'a' is an angle in radians.

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