Question

What will be the nature of roots of quadratic equation 2X^2+4X-7=0

Answer 1

D=b^2-4ac=16-4×2×-7=16+56=72>0.hence the quadratic equation has real roots.

Answer 2

For an equation ax^2 + bx +c =0

The nature of roots are determined by b^2 - 4ac

if b^2 - 4ac > 0 - real, distinct roots

b^2 - 4ac = 0 - real , equal roots

b^2 - 4ac < 0 - imaginary roots

in this equation

a = 2, b = 4,c= -7

b^2 - 4ac = 4^2 - 4*2*(-7)

= 16 + 56

= 72 >0

Therefore real and distinct roots.