Question

Use the discriminant to find the number of x-intercepts of the graph of the function.

y = x2 + 3x

Answer 1

2 x-intercepts

Explanation:

Standard form of quadratic equation:
`\sf y=ax^2+bx+c`

Given equation:
`\sf y=x^2+3x`

Therefore:

• a = 1
• b = 3
• c = 0

Discriminant:
`\sf b^2-4ac`

Substituting values into discriminant:

`\sf \implies 3^2-4(1)(0)=9`

As discriminant > 0 then 2 real roots (2 x-intercepts)