# algebra 1 - Discriminant

by Jessica
(Lowell, IN)

Use the discriminant to determine the nature of the roots of 4x2 + 15x + 10 = 0.

### Comments for algebra 1 - Discriminant

 Mar 03, 2011 Algebra 1 - Discriminant by: Staff The question: by Jessica (Lowell, IN) Use the discriminant to determine the nature of the roots of 4x2 + 15x + 10 = 0. The answer: The symbol for the discriminant of a polynomial function is often represented by the Greek letter DELTA, Δ. To type Δ on your keyboard, hold down the ALT key and type 916. Then release the ALT key. 4x² + 15x + 10 = 0 Using the quadratic formula, the roots to a quadratic equation are: ax² + bx + c = 0 x = [-b ± sqrt(b² - 4ac)]/2a The discriminant is the portion of the formula which is the square root: Δ = b² - 4ac Using the quadratic formula, the roots to your quadratic equation are: 4x² + 15x + 10 = 0 x = [-15 ± sqrt(15² - 4*4*10)]/(2*4) The discriminant for your equation is: Δ = 15² - 4*4*10 Δ = 65 The DISCRIMINANT is a POSITIVE number. A positive discriminant means that the equation will have two real roots. The final answer is: The equation will have two real roots. Thanks for writing. Staff www.solving-math-problems.com