5131039
Consider the equation \(x^2 - 1 = 3\).
a) Rewrite the equation in standard form and factor it.
b) Find the solution set.
c) If the two sides are interpreted as \(f(x) = x^2 - 1\) and \(g(x) = 3\), what do the solutions represent geometrically?
Hints
- Move all terms to one side.
- Recognize a difference of squares.
- Equal function outputs correspond to graph intersections.
Solution
1. Rewrite the equation with all terms on one side: \(x^2 - 4 = 0\).
2. Factor the difference of squares: \((x - 2)(x + 2) = 0\).
3. Therefore, \(x = -2\) or \(x = 2\).
4. Geometrically, these values are the x-coordinates of the intersection points of the graphs of \(f\) and \(g\).
Answer
a) \(x^2 - 4 = 0\), so \((x - 2)(x + 2) = 0\)
b) \(\{-2, 2\}\)
c) They are the x-coordinates of the graphs’ intersection points.
