Video: Finding the Point at Which a Constant Function Intersects the π₯- or π¦-Axes

Find the point at which the function π(π₯) = 12 intersects either the π₯ or π¦ axis.

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Video Transcript

Find the point at which the function π of π₯ equals 12 intersects either the π₯- or π¦-axis.

Our function, π of π₯ equals 12, what does that mean? What does a graph of π of π₯ equal 12 look like? Hereβs what weβre going to do. Weβre going to plug in some values of π₯ to our function to see what happens.

If π equals one in this function, what is the output? What is the solution? 12, because π of π₯ always equals 12 in this function. And when the π₯-value is negative one, the solution is still 12. So Iβll just add some numbers to my graph here and sketch this out. So now we found two points. π at one equals 12; there is that point. π at negative one also equals 12. If we plugged in π of 10, we still have 12.

Are you seeing a pattern here? The function π of π₯ equals 12 represents a horizontal line at 12. Now our question wants to know where does this function intersects the π₯- or the π¦-axis. We can tell that it does not intersect the π₯-axis. And there is the point where it intersects the π¦-axis. At point or co-ordinate zero, 12, the function π of π₯ equals 12 intersects the π¦-axis.