Precalculus Examples

$\cos (\frac{x}{2})$ , $x = 2 π$

Step 1

Replace the variable $x$ with $2 π$ in the expression.

$\cos (\frac{2 π}{2})$

Step 2

Cancel the common factor of $2$ .

Tap for more steps...

Step 2.1

Cancel the common factor.

$\cos (\frac{2 π}{2})$

Step 2.2

Divide $π$ by $1$ .

$\cos (π)$

Step 3

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the second quadrant.

$- \cos (0)$

Step 4

The exact value of $\cos (0)$ is $1$ .

$- 1 \cdot 1$

Step 5

Multiply $- 1$ by $1$ .

$- 1$

Enter YOUR Problem