Question

The quadratic equation whose roots are 1:

विकल्प

• 2x² + x – 1 = 0

• 2x² – x – 1 = 0

• 2x² + x + 1 = 0

• 2x² – x + 1 = 0

Answer 1

2x² – x – 1 = 0

Explanation:

Required quadratic equation is

`"x"^2 - (1 - 1/2)"x" + (1 xx (-1)/2) = 0`

⇒ `"x"^2 - (1/2 "x") - 1/2 = 0`

∴ 2x² – x – 1 = 0