Question

Determine if the following relations represent y as a function of x. x=y^4

Answer 1

x = y⁴ does not represent y as a function of x

Explanation:

Let's first isolate this equation for the 'y' value :

`\mathrm{Switch\:sides} : y^4=x,\\\mathrm{For\:}x^n=f\left(a\right)\mathrm{,\:n\:is\:even,\:the\:solutions\:are\:}x=\sqrt[n]{f\left(a\right)},\:-\sqrt[n]{f\left(a\right)} : y=\sqrt[4]{x},\:y=-\sqrt[4]{x}`

So as you can tell, we have two functions. However, they can be rewritten as one function, y = ± ⁴√x. As we have two values of x that correspond to one value of y, this relation is not a function.

Solution: x = y⁴ does not represent y as a function of x