Find the discriminant of the following quadratic equation.
 
1. \(2x^2 - 7x - 15 = 0\)
 
Discriminant \(=\)  
 
Nature of roots: .
 
 
2. \(5x^2 - 14x - 3 = 0\)
 
Discriminant \(=\)  
 
Nature of roots: .
 
[Note: Enter minus symbol wherever required]