Exercise 1 Page 478

Let's start by making an estimate based on the graph. Then, we can check our answer.

We can identify that the negative solution of the parabola lies roughly halfway between -1 and -2. We will estimate that x=-1.5 Now, let's check our solution. We want to increase or decrease our guess based on whether the solution is greater than or less than 0.

Guess	Check	How to revise
-1.5	(-1.5)^2-1.5-1=-0.25	decrease guess
-1.6	(-1.6)^2-1.6-1=-0.04	decrease guess
-1.61	(-1.61)^2-1.61-1=-0.0179	decrease guess
-1.619	(-1.619)^2-1.619-1=0.002161	increase guess
-1.618	(-1.618)^2-1.618-1=-0.000076	no change

The solution is between -1.618 and -1.619.