Precalculus Examples

$\cos (\arctan (\frac{11}{60}))$

Step 1

Draw a triangle in the plane with vertices $(1, \frac{11}{60})$ , $(1, 0)$ , and the origin. Then $\arctan (\frac{11}{60})$ is the angle between the positive x-axis and the ray beginning at the origin and passing through $(1, \frac{11}{60})$ . Therefore, $\cos (\arctan (\frac{11}{60}))$ is $\frac{60}{61}$ .

$\frac{60}{61}$

Step 2

The result can be shown in multiple forms.

Exact Form:

$\frac{60}{61}$

Decimal Form:

$0.98360655 \dots$