Trigonometry Examples

$\sin (- π) + \cos (5 π)$

Step 1

Simplify each term.

Tap for more steps...

Step 1.1

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.

$\sin (0) + \cos (5 π)$

Step 1.2

The exact value of $\sin (0)$ is $0$ .

$0 + \cos (5 π)$

Step 1.3

Subtract full rotations of $2 π$ until the angle is greater than or equal to $0$ and less than $2 π$ .

$0 + \cos (π)$

Step 1.4

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.

$0 - \cos (0)$

Step 1.5

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

$0 - 1 \cdot 1$

Step 1.6

Multiply $- 1$ by $1$ .

$0 - 1$

Step 2

Subtract $1$ from $0$ .

$- 1$