The value of f(x) is reflected over the y-axis.
Obtain f(1) as follows,
Draw a vertical line at x=1 to intersect the curve.
From this point of intersection, draw a horizontal line to intersect the y-axis at y=3.
Therefore, the value of f(1) is 3.
Obtain f(2) as follows,
Draw a vertical line at x=2 to intersect the curve.
From this point of intersection, draw a horizontal line to intersect the y-axis at y=8.
Therefore, the value of f(2) is 8.
Obtain f(3) as follows,
Draw a vertical line at x=3 to intersect the curve.
From this point of intersection, draw a horizontal line to intersect the y-axis at y=7.
Therefore, the value of f(3) is 7.