Q1 of 65 Page 10

In each of the following cases, let us justify & write whether the given values are the of the given quadratic equation:

8x2+7x=0,0 and -2

We know that the roots of the quadratic equation satisfies the equation.

So, if 0 and -2 are the roots of


then they must satisfy the equation.


Therefore, putting 0 in the equation we have


= 8 × 02 + 7 × 0 = 0 + 0 = 0


So, it is a root of the equation.


Putting -2 in the equation we have


= 8 × (-2)2 + 7 × (-2) = 32-14 = 18 which is not equal to 0.


So, it is also not a root of the equation.


Hence, 0 is the root of the equation.


More from this chapter

All 65 →
6

Let us construct the quadratic equations in one variable from the following statements.

There is a road of equal width around the outside of a rectangular playground having the length 45 m. and breadth 40 m. and the area of the road is 450 sqm.

 1

In each of the following cases, let us justify & write whether the given values are the of the given quadratic equation:

x2 + x+1 = 0,1 and -1

 1

In each of the following cases, let us justify & write whether the given values are the of the given quadratic equation:

and 4/3

 1

In each of the following cases, let us justify & write whether the given values are the of the given quadratic equation:

and