Question

Using the unit circle, how do you find the value of the trigonometric function: `sec -(pi/2)`?

Answer 1

`sec -(pi/2) = oo`

Explanation:

`-(pi/2) = 2pi - pi/2 = (3pi)/2`. It’s in III quadrant.

As per unit circle, coordinates are (0,-1)#

#cos theta =

`cos (-pi/2) = cos (pi/2) = 0`

Hence `sec - (pi/2) = 1 / (cos -(pi/2)) = 1 / cos (pi/2) = 1/ 0 = oo`