Find the output, y, when the input, , is 4. y Y 8 61 1 > 2 9 6 2 6 1 -6 -8+

To find the value of y at x = 4, you have to locate 4 on the x-axis. Then, draw a perpendicular line to the x-axis that passes through x = 4 and intersects the function. The intersecting point shows the desired y-value.
The procedure is shown in the next picture:
y = 1