Find the values of \(p\) for which the equation \[(p+1)x^2+4px+9=0\] has equal roots.

When does the quadratic equation \(ax^2 + bx + c = 0\) have equal roots?

The red curve here is \(y = (p+1)x^2+4px +9\).

What will the curve look like when the equation has equal roots?

Can you find the required values of \(p\)?