# Question Video: Evaluating the Output of a Function from Its Graph given Its Input Mathematics • 9th Grade

The given graph represents a function. What would be the value of the output for an input of 5?

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### Video Transcript

The given graph represents a function. What would be the value of the output for an input of five?

Our input is five, so we look for five on the 𝑥-axis. There it is. And now we look for the point on our graph which has 𝑥-coordinate five. We travel vertically from five on the 𝑥-axis until we hit this point. And reading across to the 𝑦-axis, we see that the 𝑦-coordinate of this point is two.

This point therefore has coordinates five, two. For any point on the graph of a function, the 𝑥-coordinate is the input to that function and the 𝑦-coordinate is the corresponding output, so the fact that the point five, two lies on our graph tells us that an input of five gives an output of two. And so our answer is two. The value of the output for an input of five is two.