Trigonometry Examples

$\cos (\frac{π}{20}) \cos (\frac{π}{5}) - \sin (\frac{π}{20}) \sin (\frac{π}{5})$

Step 1

The result can be shown in multiple forms.

Exact Form:

$\cos (\frac{π}{20}) \cos (\frac{π}{5}) - \sin (\frac{π}{20}) \sin (\frac{π}{5})$

Decimal Form:

$0.70710678 \dots$