Trigonometry Examples

$\sin (\frac{π}{7}) \cdot \cos (\frac{4 π}{21}) + \cos (\frac{π}{7}) \cdot \sin (\frac{4 π}{21})$

Step 1

Multiply $\cos (\frac{π}{7})$ by $\sin (\frac{4 π}{21})$ .

$\sin (\frac{π}{7}) \cos (\frac{4 π}{21}) + \cos (\frac{π}{7}) \sin (\frac{4 π}{21})$

Step 2

The result can be shown in multiple forms.

Exact Form:

$\sin (\frac{π}{7}) \cos (\frac{4 π}{21}) + \cos (\frac{π}{7}) \sin (\frac{4 π}{21})$

Decimal Form:

$0.86602540 \dots$