Trigonometry Examples

$\cos (\frac{2 π}{7}) \cos (\frac{6 π}{5}) - \sin (\frac{2 π}{7}) \sin (\frac{6 π}{5})$

Step 1

The result can be shown in multiple forms.

Exact Form:

$\cos (\frac{2 π}{7}) \cos (\frac{6 π}{5}) - \sin (\frac{2 π}{7}) \sin (\frac{6 π}{5})$

Decimal Form:

$- 0.04486483 \dots$