1) Finding the zeros of this function f(x) =x² +3x -18
f(x) = x²+3x-18 Factoring this equation, and rewriting it
Which two numbers whose sum is equal to 3 and their product is equal to 18?
6 -3 = 3 and 6 *-3 = -18
So we can rewrite as (x +6) (x-3)
(x+6)(x-3)=0 Applying the Zero product rule, to find the roots
x+6=0,
x=-6
x-3=0,
x=3
S={3,-6}
2) Setting a table, plugging in the values of x into the factored form: (x-6)(x-3)
x | y |
1 | -14 (1 +6)(1-3) =-14
2 | -8 (2 +6)(2-3) =-8
3 | 0
4 | 10
-5 | -8
-6 | 0
3) Plotting the function: