Trigonometry Examples

$2 \cos^{2} (20) - 1$

Step 1

Apply the cosine double-angle identity.

$\cos (2 \cdot 20)$

Step 2

Multiply $2$ by $20$ .

$\cos (40)$

Step 3

The result can be shown in multiple forms.

Exact Form:

$\cos (40)$

Decimal Form:

$0.76604444 \dots$

$[\begin{array}{c} x^{2} & \frac{1}{2} \\ \sqrt{π} & \int x d x \end{array}]$