WEBVTT
00:00:00.790 --> 00:00:05.170
The figure below represents the function π of π₯ equals π₯ squared plus π.
00:00:05.860 --> 00:00:09.880
Find the value of π, given the length of ππ΄ is four units.
00:00:10.660 --> 00:00:12.820
So here is the equation of our function.
00:00:13.470 --> 00:00:20.020
Since our leading term is an π₯ squared, this must be a quadratic which looks something like this, just like our graph.
00:00:20.800 --> 00:00:25.630
Now the plus π, this will shift our graph up and down.
00:00:26.360 --> 00:00:35.870
So the parent function, the original function, just π of π₯ equals π₯ squared where π is just zero, the vertex is at the point zero, zero.
00:00:36.260 --> 00:00:41.220
So looking at our figure, itβs been moved down four units.
00:00:41.500 --> 00:00:45.490
And we also know this because the length of ππ΄ is four units.
00:00:46.340 --> 00:00:50.900
So if we went down four, π must be negative four.
00:00:51.430 --> 00:00:54.350
Therefore, π equals negative four would be our final answer.