Which of the following are solutions to the equation [tex]\sin x \cos x=\frac{\sqrt{3}}{4}[/tex]? Check all that apply.

A. [tex]\frac{\pi}{12} + n \pi[/tex]

B. [tex]\frac{\pi}{12} + \frac{n \pi}{2}[/tex]

C. [tex]\frac{2 \pi}{6} + n \pi[/tex]

D. [tex]\frac{\pi}{6} + n \pi[/tex]



Answer :

To determine which of the given options solve the equation \(\sin x \cos x = \frac{\sqrt{3}}{4}\), we can start by using a trigonometric identity and checking each option step-by-step.

First, let's use the double-angle identity for sine, which states:
[tex]\[ \sin(2x) = 2 \sin(x) \cos(x) \][/tex]
We can rewrite the given equation using this identity:
[tex]\[ \sin x \cos x = \frac{\sqrt{3}}{4} \Rightarrow 2 \sin x \cos x = \frac{\sqrt{3}}{2} \Rightarrow \sin(2x) = \frac{\sqrt{3}}{2} \][/tex]

Next, we need to determine the angles for which \(\sin(2x) = \frac{\sqrt{3}}{2}\).

The value \(\frac{\sqrt{3}}{2}\) corresponds to angles:
[tex]\[ 2x = \frac{\pi}{3} + 2k\pi \quad \text{or} \quad 2x = \pi - \frac{\pi}{3} + 2k\pi \][/tex]
where \(k\) is any integer.

Simplifying these equations gives:
[tex]\[ 2x = \frac{\pi}{3} + 2k\pi \quad \text{or} \quad 2x = \frac{2\pi}{3} + 2k\pi \][/tex]
Solving for \(x\):
[tex]\[ x = \frac{\pi}{6} + k\pi \quad \text{or} \quad x = \frac{\pi}{3} + k\pi \][/tex]
where \(k\) is any integer.

Now we check each given option to see if they match either \(x = \frac{\pi}{6} + k\pi\) or \(x = \frac{\pi}{3} + k\pi\):

A. \(\frac{\pi}{12} + n\pi\)

This does not match. Simplifying it further does not yield either \(\frac{\pi}{6} + k\pi\) or \(\frac{\pi}{3} + k\pi\).

B. \(\frac{\pi}{12} + \frac{n\pi}{2}\)

This also does not match. Simplifying it further does not yield either \(\frac{\pi}{6} + k\pi\) or \(\frac{\pi}{3} + k\pi\).

C. \(\frac{2\pi}{6} + n\pi\)

Simplifying this gives:
[tex]\[ \frac{2\pi}{6} = \frac{\pi}{3} \][/tex]
Thus, \(x = \frac{\pi}{3} + n\pi\), which matches one of our derived solutions.

D. \(\frac{\pi}{6} + n\pi\)

This matches exactly one of our derived solutions.

Therefore, the correct options are:
[tex]\[ \boxed{C \text{ and } D} \][/tex]
Choices C ([tex]\(\frac{2\pi}{6} + n\pi\)[/tex]) and D ([tex]\(\frac{\pi}{6} + n\pi\)[/tex]) are indeed correct solutions to the equation [tex]\(\sin x \cos x = \frac{\sqrt{3}}{4}\)[/tex].

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