Q1.    Check whether the following are quadratic equations :                (vii)    $(x+2)^3 = 2x(x^2 -1)$

L.H.S. $(x+2)^3$ can be written as:

$= x^3+8+6x(x+2) =x^3+6x^2+12x+8$

and R.H.S $2x(x^2-1)$ can be written as:

$= 2x^3-2x$

$\Rightarrow x^3+6x^2+12x+8 = 2x^3-2x$

i.e., $x^3-6x^2-14x-8 = 0$

This equation is NOT of type: $ax^2+bx+c = 0$.

Hence, the given equation is not a quadratic equation.

Exams
Articles
Questions