Question

How do you solve the equation by graphing `x^2 - 18x + 81 = 0`?

Answer 1

Factorise and sketch!

Explanation:

If `x^2 -18x+81=0`, then it follows that `(x-9)^2=0` through factorisation. Therefore `x` can only equal `9` for only that value satisfies the above equation.

To sketch this, you know that `(9,0)` is your one and only `x`-intercept, and that your graph will turn at that coordinate too. Your `y`-intercept, reading from your original equation is at `(0, 81)`.