WEBVTT 00:00:00.960 --> 00:00:10.230 The curve of a quadratic function 𝑓 intersects the π‘₯-axis at the points one, zero and negative four, zero. 00:00:11.240 --> 00:00:15.330 What is the solution set of the equation 𝑓 of π‘₯ equals zero? 00:00:16.730 --> 00:00:18.240 Let’s sketch out what we know. 00:00:19.940 --> 00:00:29.170 We know that 𝑓 intersects the π‘₯-axis at these two points: one, zero and negative four, zero. 00:00:29.990 --> 00:00:33.250 We also know that we’re dealing with a quadratic function. 00:00:34.310 --> 00:00:37.060 Maybe the quadratic function looks like this. 00:00:37.890 --> 00:00:39.510 Maybe it looks like this. 00:00:40.530 --> 00:00:44.450 But we don’t actually need that information to find the solution set. 00:00:45.460 --> 00:00:53.130 The place where 𝑓 of π‘₯ equals zero is the π‘₯ value of the π‘₯-intercepts. 00:00:54.170 --> 00:01:01.190 This happens at π‘₯ equals negative four and π‘₯ equal to positive one. 00:01:01.820 --> 00:01:08.200 Our solution set is the set of these two π‘₯ values: negative four and one.