Solve for x in Radians sin(x)^2=3cos(x)^2

Solve Math

Trigonometry

$\sin^{2} (x) = 3 \cos^{2} (x)$

Subtract $3 \cos^{2} (x)$ from both sides of the equation.

$\sin^{2} (x) - 3 \cos^{2} (x) = 0$

Replace the $\sin^{2} (x)$ with $1 - \cos^{2} (x)$ based on the $\sin^{2} (x) + \cos^{2} (x) = 1$ identity.

$(1 - \cos^{2} (x)) - 3 \cos^{2} (x) = 0$

Subtract $3 \cos^{2} (x)$ from $- \cos^{2} (x)$ .

$1 - 4 \cos^{2} (x) = 0$

Reorder the polynomial.

$- 4 \cos^{2} (x) + 1 = 0$

Subtract $1$ from both sides of the equation.

$- 4 \cos^{2} (x) = - 1$

Divide each term in $- 4 \cos^{2} (x) = - 1$ by $- 4$ and simplify.

Tap for more steps...

Divide each term in $- 4 \cos^{2} (x) = - 1$ by $- 4$ .

$\frac{- 4 \cos^{2} (x)}{- 4} = \frac{- 1}{- 4}$

Simplify the left side.

Tap for more steps...

Cancel the common factor of $- 4$ .

Tap for more steps...

Cancel the common factor.

$\frac{- 4 \cos^{2} (x)}{- 4} = \frac{- 1}{- 4}$

Divide $\cos^{2} (x)$ by $1$ .

$\cos^{2} (x) = \frac{- 1}{- 4}$

Simplify the right side.

Tap for more steps...

Dividing two negative values results in a positive value.

$\cos^{2} (x) = \frac{1}{4}$

Take the square root of both sides of the equation to eliminate the exponent on the left side.

$\cos (x) = \pm \sqrt{\frac{1}{4}}$

Simplify $\pm \sqrt{\frac{1}{4}}$ .

Tap for more steps...

Rewrite $\sqrt{\frac{1}{4}}$ as $\frac{\sqrt{1}}{\sqrt{4}}$ .

$\cos (x) = \pm \frac{\sqrt{1}}{\sqrt{4}}$

Any root of $1$ is $1$ .

$\cos (x) = \pm \frac{1}{\sqrt{4}}$

Simplify the denominator.

Tap for more steps...

Rewrite $4$ as $2^{2}$ .

$\cos (x) = \pm \frac{1}{\sqrt{2^{2}}}$

Pull terms out from under the radical, assuming positive real numbers.

$\cos (x) = \pm \frac{1}{2}$

The complete solution is the result of both the positive and negative portions of the solution.

Tap for more steps...

First, use the positive value of the $\pm$ to find the first solution.

$\cos (x) = \frac{1}{2}$

Next, use the negative value of the $\pm$ to find the second solution.

$\cos (x) = - \frac{1}{2}$

The complete solution is the result of both the positive and negative portions of the solution.

$\cos (x) = \frac{1}{2}, - \frac{1}{2}$

Set up each of the solutions to solve for $x$ .

$\cos (x) = \frac{1}{2}$

$\cos (x) = - \frac{1}{2}$

Solve for $x$ in $\cos (x) = \frac{1}{2}$ .

Tap for more steps...

Take the inverse cosine of both sides of the equation to extract $x$ from inside the cosine.

$x = \arccos (\frac{1}{2})$

Simplify the right side.

Tap for more steps...

The exact value of $\arccos (\frac{1}{2})$ is $\frac{π}{3}$ .

$x = \frac{π}{3}$

The cosine function is positive in the first and fourth quadrants. To find the second solution, subtract the reference angle from $2 π$ to find the solution in the fourth quadrant.

$x = 2 π - \frac{π}{3}$

Simplify $2 π - \frac{π}{3}$ .

Tap for more steps...

To write $2 π$ as a fraction with a common denominator, multiply by $\frac{3}{3}$ .

$x = 2 π \cdot \frac{3}{3} - \frac{π}{3}$

Combine fractions.

Tap for more steps...

Combine $2 π$ and $\frac{3}{3}$ .

$x = \frac{2 π \cdot 3}{3} - \frac{π}{3}$

Combine the numerators over the common denominator.

$x = \frac{2 π \cdot 3 - π}{3}$

Simplify the numerator.

Tap for more steps...

Multiply $3$ by $2$ .

$x = \frac{6 π - π}{3}$

Subtract $π$ from $6 π$ .

$x = \frac{5 π}{3}$

Find the period of $\cos (x)$ .

Tap for more steps...

The period of the function can be calculated using $\frac{2 π}{| b |}$ .

$\frac{2 π}{| b |}$

Replace $b$ with $1$ in the formula for period.

$\frac{2 π}{| 1 |}$

The absolute value is the distance between a number and zero. The distance between $0$ and $1$ is $1$ .

$\frac{2 π}{1}$

Divide $2 π$ by $1$ .

$2 π$

The period of the $\cos (x)$ function is $2 π$ so values will repeat every $2 π$ radians in both directions.

$x = \frac{π}{3} + 2 π n, \frac{5 π}{3} + 2 π n$ , for any integer $n$

Solve for $x$ in $\cos (x) = - \frac{1}{2}$ .

Tap for more steps...

Take the inverse cosine of both sides of the equation to extract $x$ from inside the cosine.

$x = \arccos (- \frac{1}{2})$

Simplify the right side.

Tap for more steps...

The exact value of $\arccos (- \frac{1}{2})$ is $\frac{2 π}{3}$ .

$x = \frac{2 π}{3}$

The cosine function is negative in the second and third quadrants. To find the second solution, subtract the reference angle from $2 π$ to find the solution in the third quadrant.

$x = 2 π - \frac{2 π}{3}$

Simplify $2 π - \frac{2 π}{3}$ .

Tap for more steps...

To write $2 π$ as a fraction with a common denominator, multiply by $\frac{3}{3}$ .

$x = 2 π \cdot \frac{3}{3} - \frac{2 π}{3}$

Combine fractions.

Tap for more steps...

Combine $2 π$ and $\frac{3}{3}$ .

$x = \frac{2 π \cdot 3}{3} - \frac{2 π}{3}$

Combine the numerators over the common denominator.

$x = \frac{2 π \cdot 3 - 2 π}{3}$

Simplify the numerator.

Tap for more steps...

Multiply $3$ by $2$ .

$x = \frac{6 π - 2 π}{3}$

Subtract $2 π$ from $6 π$ .

$x = \frac{4 π}{3}$

Find the period of $\cos (x)$ .

Tap for more steps...

The period of the function can be calculated using $\frac{2 π}{| b |}$ .

$\frac{2 π}{| b |}$

Replace $b$ with $1$ in the formula for period.

$\frac{2 π}{| 1 |}$

The absolute value is the distance between a number and zero. The distance between $0$ and $1$ is $1$ .

$\frac{2 π}{1}$

Divide $2 π$ by $1$ .

$2 π$

The period of the $\cos (x)$ function is $2 π$ so values will repeat every $2 π$ radians in both directions.

$x = \frac{2 π}{3} + 2 π n, \frac{4 π}{3} + 2 π n$ , for any integer $n$

List all of the solutions.

$x = \frac{π}{3} + 2 π n, \frac{5 π}{3} + 2 π n, \frac{2 π}{3} + 2 π n, \frac{4 π}{3} + 2 π n$ , for any integer $n$

Consolidate the solutions.

Tap for more steps...

Consolidate $\frac{π}{3} + 2 π n$ and $\frac{4 π}{3} + 2 π n$ to $\frac{π}{3} + π n$ .

$x = \frac{π}{3} + π n, \frac{5 π}{3} + 2 π n, \frac{2 π}{3} + 2 π n$ , for any integer $n$

Consolidate $\frac{5 π}{3} + 2 π n$ and $\frac{2 π}{3} + 2 π n$ to $\frac{2 π}{3} + π n$ .

$x = \frac{π}{3} + π n, \frac{2 π}{3} + π n$ , for any integer $n$

Do you know how to Solve for x in Radians sin(x)^2=3cos(x)^2? If not, you can write to our math experts in our application. The best solution for your task you can find above on this page.