Question

At what points does the graph of the function `f(x) = x^2 + 2x-15` cross the x-axis?

Answer 1

The definition of when a graph crosses the x-axis is the "x-intercept". The x intercepts can be found by setting `y` to `0` and solving for `x`.

`0 = x^2 + 2x - 15`

`0 = (x + 5)(x - 3)`

`x = -5 and 3`

Hence, the graph will cross the x-axis at `(-5, 0)` and `(3, 0)`.

Hopefully this helps!