Find the Exact Value arccos(cos(-pi/7))

$\arccos (\cos (- \frac{π}{7}))$

Step 1

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

$\arccos (\cos (\frac{13 π}{7}))$

Step 2

The result can be shown in multiple forms.

Exact Form:

$\arccos (\cos (\frac{13 π}{7}))$

Decimal Form:

$0.44879895 \dots$