#### Answer

a) The limit of f(x) and x approaches three from the left side is infinity.
b)The limit of f(x) and x approaches four from the right side is negative infinity.

#### Work Step by Step

Putting a - or + sign above the bounds of a limit indicates which side of the function we are approaching. For (a), as we pass through points with x values of 1, 2, 2.5, 2.9, 2.99, the limit gets closer and closer to positive infinity. For (b), as we pass through points with x values of 5, 4, 3.5, 3.1, 3.01, the limit gets closer and closer to negative infinity.