Two Answers: x = 2 and x = 10
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Explanation:
Draw a horizontal line through 10 on the y axis. This is because R(x) = 10 is the same as y = 10. The output of the function is the y value.
See the diagram below.
The horizontal line crosses the parabola at two locations. From those points, draw a vertical line straight down to the x axis. Note how we land at x = 2 and x = 10. This means that R(2) = 10 and R(10) = 10.
