Domain of f is x >= 0
Fragment of a discussion from Science talk:Math Exam Resources/Courses/MATH100/December 2013/Question 08 (a)
Pardon my ignorance, but why is the function not defined for x < 0? At x = -1, is its value not 77? and . . Please help me to understand if I am overlooking something.
Nicholas Hu (talk)
You are absolutely right! This works because of the odd denominator in the fractional power. I was confused because, in general, the n-th root of a negative number has n solutions, if you allow complex numbers. This is also the reason why google & wolframalpha etc tell you that (-1)^(2/7) is a complex number. None of that fanciness is necessary here, and your solution is very clear. Good job.