In the third degree polynomial function f(x) =x^3 + 4x, why are 2i and -2i zeros?

Astandard american eskimo dog has a mean weight of 30 pounds with a standard deviation of 2 pounds. assuming the weights of standard eskimo dogs are normally distributed, what range of weights would 99.7% of the dogs have? approximately 26–34 pounds approximately 24–36 pounds approximately 28–32 pounds approximately 29–31 pounds

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

List the sides of δrst in in ascending order (shortest to longest) if: m∠r =x+28°, m∠s = 2x+16°, and m∠t = x+12°