Secant is a trigonometric function that is the reciprocal of the function cosine. This means that in a cartesian plane, the value of secant is equal to r / x. For the values to be undefined, x should be zero. The angles are π/2 and 3π/2. The answers are B and D.
All the edges of a cube have the same length, and the volume of a cube is the length of an edge taken to the third power. So the length of the edge of a cube with a volume of 125 is 5.