Find the discriminant.

4v2+9v=0
How many real solutions does the equation have?

1 answer

To find the discriminant of the quadratic equation \(4v^2 + 9v = 0\), we first want to express it in the standard form \(ax^2 + bx + c = 0\).

The given equation can be rewritten as:

\[ 4v^2 + 9v + 0 = 0 \]

Here, we identify:

  • \( a = 4 \)
  • \( b = 9 \)
  • \( c = 0 \)

The discriminant \( D \) of a quadratic equation is given by the formula:

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

Substituting the values of \( a \), \( b \), and \( c \):

\[ D = 9^2 - 4 \cdot 4 \cdot 0 \] \[ D = 81 - 0 \] \[ D = 81 \]

Now, we can analyze the discriminant to determine how many real solutions the equation has. The rules for the number of real solutions based on the discriminant are:

  • If \( D > 0 \), there are 2 distinct real solutions.
  • If \( D = 0 \), there is exactly 1 real solution (a double root).
  • If \( D < 0 \), there are no real solutions.

Since \( D = 81 \), which is greater than 0, the equation \(4v^2 + 9v = 0\) has 2 distinct real solutions.