Question

Which of the following is not a quadratic equation?

विकल्प

• 3x – x² = x² + 5

• (x + 2)² = 2(x² – 5)

• `(sqrt(2)x + 3)^2 = 2x^2 + 6`

• (x – 1)² = 3x² + x – 2

Answer 1

`bb((sqrt(2)x + 3)^2 = 2x^2 + 6)`

Explanation:

∵ `(sqrt(2)x + 3)^2 = 2x^2 + 6` 

⇒ `2x^2 + 9 + 6sqrt(2)x = 2x^2 + 6` 

⇒ `6sqrt(2)x + 3 = 0`, which is not a quadratic equation