How do you find the value of the discriminant and determine the nature of the roots 2p^2+5p-4?

1 Answer
Jun 6, 2017

Delta = 57 > 0 is not a perfect square, so the zeros are distinct, real and irrational.

Explanation:

Given:

2p^2+5p-4

Note that this is written in standard form:

ap^2+bp+c

with a=2, b=5 and c=-4

The discriminant Delta is given by the formula:

Delta = b^2-4ac

color(white)(Delta) = color(blue)(5)^2-4(color(blue)(2))(color(blue)(-4))

color(white)(Delta) = 25+32

color(white)(Delta) = 57

Since Delta > 0 the given quadratic has two distinct real zeros. Since Delta = 57 is not a perfect square, those zeros are irrational.

The zeros of 2p^2+5p-4 are the roots of the equation:

2p^2+5p-4 = 0