Q1 of 108 Page 40

Check whether the following are quadratic equations:

x3 + 3x + 1 = (x – 2)2


Let us solve the above equation,

x3 + 3x + 1 = (x – 2)2


x3 + 3x + 1 = x2 – 2 × 2 × x + 4 …….. [(a-b) 2 = a2 – 2ab + b2]


x3 + 3x + 1 = x2 – 4x + 4


x3 + 3x + 1 - x2 + 4x - 4 = 0


x3 - x2 + 7x - 3 = 0


Since on solving the equation we do get the third power of x along with second power which proves that the following set of equation is not quadratic. A quadratic equation contain the highest power of x which is 2.


More from this chapter

All 108 →
1

Check whether the following are quadratic equations:

x(x + 1) + 8 = (x + 2) (x – 2)


 1

Check whether the following are quadratic equations:

(x + 2)3 = x3 – 4


 1

Check whether the following are quadratic equations:


 2

Solve the following equations by factorization method:

2x2 – 5x + 3 = 0