If you ignore the friction, the amount of time required for a box to slide down an inclined plane is √(2a/g•sin(theta)•cos(theta)), where a is the horizontal distance defined by the inclined plane, g is the acceleration due to gravity and theta is the angle of the inclined plane. For what values of theta is the expression undefined?
A. 0°
B. 90°
C. Both A and B
D. None

Given:

The time required for a box to slide down an inclined plane is

where,

g be the,acceleration due to gravity.

be the inclined plane.

To find the value of for which the given expression is undefined.

Now,

T will be undefined if the denominator is 0.

⇒

or, [ g ≠ 0 it is a constant]

either or

For, ⇒

Again,

For, ⇒

Hence,

The expression will be undefined for the value of 0° and 90° of θ.

Option C.