Trigonometry Examples

$\cos (- \frac{1}{5} + \frac{3}{5})$

Step 1

Combine the numerators over the common denominator.

$\cos (\frac{- 1 + 3}{5})$

Step 2

Add $- 1$ and $3$ .

$\cos (\frac{2}{5})$

Step 3

The result can be shown in multiple forms.

Exact Form:

$\cos (\frac{2}{5})$

Decimal Form:

$0.92106099 \dots$