what do you mean by coincident roots?

Refer the following links also :

https://www.meritnation.com/ask-answer/question/find-the-values-of-p-for-which-the-quadratic-equation-x2-px/complex-numbers-and-quadratic-equations/2859180

https://www.meritnation.com/ask-answer/question/3-for-what-value-of-p-the-equation-1-p-x2-2-1-2p-x/quadratic-equations/8506375

**
**