Question

Use the figures to evaluate the function given that f (x) = sin x,   g (x) = cos x,    and   h (x) = tan x.

f (α/2)

Answer 1

Step 1 :

Find .

The function .

The point is on the circle.

.

Compare the equation with .

Radius of the circle .

The point is on a circle of radius 1.

From the figure, angle lies in third quadrant.

Half-angle formula : .

.

       (Since lies in third quadrant.)

.

Solution :

.