Question

At which value will the graph of y= sec x have a zero?

A.) pi/2
B.) pi/4
C.) pi/3
D.) None

Answer 1

D: None of the Above

Answer 2

Correct option is D.

Explanation:

Given the graph y=sec x

we have to choose the value at which the value of y is 0.

as,
`sec x=(1)/(cos x)`

Option A.)
`(\pi)/(2)`

`y=sec{(\pi)/(2)}=\frac{1}{cos{\pi}{2}}=(1)/(0)=\infty`

Option B.)
`(\pi)/(2)`

`y=sec{(\pi)/(4)}=\frac{1}{cos{\pi}{4}}=(1)/((1)/(\sqrt 2))=\sqrt2`

Option C.)
`(\pi)/(3)`

`y=sec{(\pi)/(3)}=\frac{1}{cos{\pi}{3}}=(1)/((1)/(2))=2`

No option above gives the value 0

Hence, the correct option is D.