Question

Which of the following are quadratic equation in x? 

`x^2-1/x^2=5` 

 

Answer 1

`x^2-1/x^2=5x^2` 

`⇒x^4-1=5x^2` 

`⇒x^4-5x^2-1=0` 

`(x^4-5x^2-1)`is a polynomial with degree 4. 

∴` x^2-5x^2-1=0` is not a quadratic equation