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What is the exact value of sin (165 degrees)

What is the exact value of sin (165 degrees)-example-1

2 Answers

5 votes

Answer:

Explanation:

(√6 - √2)/4

User Alin Stelian
by
3.2k points
7 votes

The exact value of
$\sin(165^\circ)$ is
$\frac{\sqrt{2-√(3)}}{4}$, which is option C.

The exact value of
$\sin(165^\circ)$ is
$\frac{\sqrt{2-√(3)}}{4}$. This corresponds to option C.

To find this value, we can use the angle addition formula for sine:


$\sin(a+b) = \sin a \cos b + \cos a \sin b$

In this case, we can rewrite
$165^\circ$ as the sum of
$60^\circ$ and
$105^\circ$. So, we have:


$\sin(165^\circ) = \sin(60^\circ + 105^\circ)$

Now, let's use the values of sine and cosine for
$60^\circ$ and
$105^\circ$:


$\sin(165^\circ) = \sin(60^\circ)\cos(105^\circ) + \cos(60^\circ)\sin(105^\circ)$


$\sin(165^\circ) = (√(3))/(2)\cdot(√(2)+√(6))/(4) + (1)/(2)\cdot(√(2)-√(6))/(4)$

Simplifying this expression, we get:


$\sin(165^\circ) = \frac{\sqrt{2+√(3)}}{4}$

Therefore, option C is the correct answer.

User Marcel Blanck
by
3.9k points