McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
5. Solving Quadratic Equations by Using the Quadratic Formula
Continue to next subchapter

Exercise 56 Page 138

The discriminant of a quadratic equation is b^2-4ac.

Two

Practice makes perfect
In a quadratic equation, both a and b are greater than 0 and c is less than 0. ax^2+bx+c=0

We want to determine the number of solutions of the equation. To do so, we will use the discriminant of the quadratic equation. In the Quadratic Formula, b^2-4ac is the discriminant. ax^2+bx+c=0 ⇕ x=- b±sqrt(b^2-4ac)/2a Let's determine the sign of the discriminant. b^2_(>0) -4ac_(>0) >0 Since a square of a number is positive and the product of two negative numbers is positive, the discriminant of the equation is always positive. This means that the equation has two real solutions.