Answer:
x ≥ 0
Step-by-step explanation:
A function is one-to-one if it passes the horizontal line test
The horizontal line test states that a horizontal line should not intersect the graph of the function at more than one point
Essentially it means for output value should correspond to only one input value
Looking at the graph we see that it fails the horizontal line test
For example we get the same output of 2 for x = - 1 and x = +1
This is because of the x² term which yields the same value for x negative and x positive
If we restrict ourselves only to all negative or all positive values of x (including zero) this problem will be eliminated
Answer
So to make the function one-to-one restrict domain as follows
x ≥ 0
