Question

Find the Discriminant of quadratic equations 

(i) 2x² - 7x + 6 = 0

(ii) 3x² - 2x + 8 = 0

(iii) 2x² - 5\(\sqrt{2x}\) + 4 = 0

Answer 1

(i) 2x² - 7x + 6 = 0

Here 

a = 2

b = - 7

c = 6

Discriminant D is diven by: 

D = b² - 4ac

= (-7)² - 4 x 2 x 6

= 49 - 48

= 1

(ii) 3x² - 2x + 8 = 0

Here

a = 3,

b = -2,

c = 8

Discriminant D is given by:

D = b² - 4ac

= (-2)² - 4 x 3 x 8

= 4 - 96

= - 92

(iii) 2x² - 5\(\sqrt{2x}\) + 4 = 0

Here

a = 2

b = - 5√2.

c = 4

Discriminant D is given by:

D = b² - 4ac

= (- 5√2)² - 4 x 2 x 4

= (25 x 2) - 32

= 50 - 32

= 18