Which of the following is a quadratic equation?
A. x³ + 2x + 1 = x² + 3
B. – 2x = (5 – x) (2x –Â \( \frac{2}{5} \))
C. ( k + 1 )x² +\( \frac{3}{2} \)x=7, where k = -1
D. x³x² = (x³)
ANSWER
Option A – has no real roots
Option B is independent of term x²
Option C is also independent of term x² for k= -1
Option D implies
x² =1
x= ±1
Hence answer is Option D
how do we state the nature of quadratics
A polynomial can have real numbers as zero(ie rational and irrational)to decide it’s nature we can use the relationship between the coefficients and zero (by comparing sum and product of zeroes)