For an equation ax^2 + bx + c = 0, its roots are I. Real and different if b^2 > 4ac. II. Imaginary and equal if b^2 < 4ac.

Instructions

Each question below has two statements, I and II. Mark your answer as:

Question 111

For an equation $$ax^2 + bx + c = 0$$, its roots are
I. Real and different if $$b^2 > 4ac.$$
II. Imaginary and equal if $$b^2 < 4ac.$$

Solution

For an equation $$ax^2 + bx + c = 0$$,

the roots are : $$\frac{-b\pm \sqrt{b^2-4ac}}{2a}$$

Now, if $$b^2>4ac$$, roots are real and different.

If $$b^2=4ac$$, roots are equal.

If $$b^2<4ac$$, roots are imaginary.

Thus, only first statement is true.

=> Ans - (A)

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