Precalculus Examples

$y = 3 \cos (\frac{π}{4})$

Step 1

The exact value of $\cos (\frac{π}{4})$ is $\frac{\sqrt{2}}{2}$ .

$y = 3 \frac{\sqrt{2}}{2}$

Step 2

Combine $3$ and $\frac{\sqrt{2}}{2}$ .

$y = \frac{3 \sqrt{2}}{2}$

Step 3

The result can be shown in multiple forms.

Exact Form:

$y = \frac{3 \sqrt{2}}{2}$

Decimal Form:

$y = 2.12132034 \dots$