Find the discriminant.

4u2–9u–7=0
How many real solutions does the equation have?

1 answer

To find the discriminant of the quadratic equation \(4u^2 - 9u - 7 = 0\), we can use the formula for the discriminant \(D\) of a quadratic equation in the form \(au^2 + bu + c = 0\):

\[ D = b^2 - 4ac \]

Here, the coefficients are:

  • \(a = 4\)
  • \(b = -9\)
  • \(c = -7\)

Now, we can substitute these values into the discriminant formula:

\[ D = (-9)^2 - 4(4)(-7) \]

Calculating each term:

  1. \( (-9)^2 = 81 \)
  2. \( 4 \times 4 \times -7 = -112\)
  3. Thus, \( D = 81 - (-112) = 81 + 112 = 193 \)

Now, \(D = 193\).

Since the discriminant \(D\) is greater than 0, \(D > 0\), this indicates that the quadratic equation has two distinct real solutions.