Answer:
![\boxed {\boxed {\sf -63}}](https://img.qammunity.org/2021/formulas/mathematics/high-school/gihukj1zzi8f0em2lhubn5lqa19yt0y5t2.png)
Explanation:
The discriminant is the portion of the Quadratic Formula that is under a square root. It helps us identify if a function has 2,1, or 0 solutions.
The quadratic formula is:
![{x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}}](https://img.qammunity.org/2021/formulas/mathematics/high-school/15if1eey7cjnzxgrnr4p0fx0mfzrz6qdof.png)
where the quadratic is: ax²+bx+c
The part under the square root is just:
![b^2-4ac}](https://img.qammunity.org/2021/formulas/mathematics/high-school/aun4mfrbcigh7l2a3fkxhc9uh0v6nzdzqg.png)
We are given the quadratic:
x² -3x+18
Therefore,
- a= 1 (there is an implied coefficient of 1 in front of the x²)
- b= -3
- c= 18
Substitute the values into the formula for the discriminant.
![(-3)^2-4(1)(18)}](https://img.qammunity.org/2021/formulas/mathematics/high-school/372bn28169k5q25js7g2dkc7k05a8bonav.png)
Solve the exponent.
![9-4(1)(18)}](https://img.qammunity.org/2021/formulas/mathematics/high-school/qh454idgjklis6281tqx37ea2q9gvn1ljc.png)
Multiply.
![9-72](https://img.qammunity.org/2021/formulas/mathematics/high-school/w5hjuy06iol2c04ir7i7yodspr2dyuyrie.png)
Subtract
![-63](https://img.qammunity.org/2021/formulas/mathematics/high-school/6rwn277df8ci5x7ixe8wesyn9fdny67swn.png)
Since the discriminant is negative, there are no real solutions. There are imaginary solutions though.