Trigonometry Examples

$\cos (4 x) = \cos (- 3 x)$

Step 1

For the two functions to be equal, the arguments of each must be equal.

$4 x = - 3 x$

Step 2

Move all terms containing $x$ to the left side of the equation.

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Step 2.1

Add $3 x$ to both sides of the equation.

$4 x + 3 x = 0$

Step 2.2

Add $4 x$ and $3 x$ .

$7 x = 0$

Step 3

Divide each term in $7 x = 0$ by $7$ and simplify.

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Step 3.1

Divide each term in $7 x = 0$ by $7$ .

$\frac{7 x}{7} = \frac{0}{7}$

Step 3.2

Simplify the left side.

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Step 3.2.1

Cancel the common factor of $7$ .

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Step 3.2.1.1

Cancel the common factor.

$\frac{7 x}{7} = \frac{0}{7}$

Step 3.2.1.2

Divide $x$ by $1$ .

$x = \frac{0}{7}$

Step 3.3

Simplify the right side.

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Step 3.3.1

Divide $0$ by $7$ .

$x = 0$