Question

which of the following equation has no real roots
(1) 2x^2-3√2+9/4=0
(2) x^2+x-5=0
(3)x^2+3x+2√2
(4)5x^2-3x+1 ​

Answer 1

Note : c(a) means coefficient of a

Answer:

(3)x^2+3x+2√2=0

Step-by-step explanation:

To check if an equation has unreal roots or not, we just need to check if

c(x)^2>4*c(x^2)*c(x^0)

In the third equation, the condition

3^2>4*1*2√2

9>8√2

Is not true.

So the equation doesn't have real roots.