94.4k views
5 votes
Find the value of x in the intervals for the equation sin2x = cos x.

User Sanjivr
by
7.6k points

1 Answer

3 votes

Final Answer:

The value of x in the intervals for the equation
\( \sin(2x) = \cos(x) \) is
\( x = (\pi)/(6) + n\pi \), where
\( n \) is an integer.

Step-by-step explanation:

To find the value of
\( x \) in the given equation,
\( \sin(2x) = \cos(x) \), we can use trigonometric identities. First, let's rewrite the equation using double-angle and basic trigonometric identities:


\[ \sin(2x) = \cos(x) \]

Using the double-angle identity
\( \sin(2x) = 2\sin(x)\cos(x) \), we get:


\[ 2\sin(x)\cos(x) = \cos(x) \]

Now, we can simplify by dividing both sides by
\( \cos(x) \) (assuming \( \cos(x) \\eq 0 \)):


\[ 2\sin(x) = 1 \]

Dividing both sides by 2:


\[ \sin(x) = (1)/(2) \]

This gives us
\( x = (\pi)/(6) + n\pi \), where
\( n \) is an integer. The solution is periodic because the sine function repeats every
\( 2\pi \) radians.

In conclusion, the solution to the equation
\( \sin(2x) = \cos(x) \) is
\( x = (\pi)/(6) + n\pi \), where
\( n \) can take any integer value. This represents the intervals in which the equation holds true, considering the periodic nature of trigonometric functions.

User Hotpink
by
8.6k points

No related questions found