Finite Math Examples

$\arccos (\cos (\frac{15 π}{2}))$

Step 1

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

$\arccos (\cos (\frac{3 π}{2}))$

Step 2

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

$\arccos (\cos (\frac{π}{2}))$

Step 3

The exact value of $\cos (\frac{π}{2})$ is $0$ .

$\arccos (0)$

Step 4

The exact value of $\arccos (0)$ is $\frac{π}{2}$ .

$\frac{π}{2}$

Step 5

The result can be shown in multiple forms.

Exact Form:

$\frac{π}{2}$

Decimal Form:

$1.57079632 \dots$