An equilateral triangle has a perimeter of 15x^3+33x^5 feet. What is the length of each side?

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

Pls me this is due today and i need i will make brainliest if you me answer correctly and i will report if you try to give me a dumb answer.

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !