Option 4 : cx^{2} + bx + a = 0

RBI Grade B 2020: Full Mock Test

9645

200 Questions
200 Marks
120 Mins

**Given**

p, q are the roots of ax2 + bx + c = 0

**Formulae Used**

Sum of roots = -b/a

Product of roots = c/a

a Quadratic Equation can be written as x^{2 }– ( sum of roots )x + ( product of roots ) = 0

**Calculation**

From ax2 + bx + c = 0, we get p + q = -b/a, pq = c/a

The Quadratic equation with roots 1/p, 1/q = x^{2} – (1/p + 1/q)x + 1/pq = 0

1/p + 1/q = (p + q)/pq

⇒ (-b/a) / (c/a) = -b/c

1/pq = a/c

⇒ x^{2} – (-b/c)x + a/c = 0

⇒ cx^{2} + bx + a = 0

**∴ The required equation is cx2 + bx + a = 0 **