Quadratic Equations Worksheet With Answer Key (Page 4 of 7) in pdf

Quadratic Equations Worksheet With Answer Key Page 4

Example:

Without finding the actual roots of 2x

+ 3x – 5 = 0, find its sum of roots and product of

roots.

Solution:

comparing to ax

+ bx + c = 0, we get a = 2, b = 3 and c = -5.

So,

−

sum of roots =

= -3/ 2.

product of roots

= -5/2

[Note: you can verify the result by actual calculation of roots ]

D. class works.

1. Write the nature of roots of the following quadratic equations.

– 2x + 5 = 0

ii) x

– 2x - 3 = 0

ii)

– 2x - 5 = 0

iv) x

– 2x + 1 = 0

2. Find the sum and product of roots of 3x

– 2x - 3 = 0

3. Calculate the sum and product of roots of x

– 2x - 5 = 0

Lecture – 26 (50 minutes)

a) Formation of a quadratic equations.

b) Quadratic inequalities and their solution sets.

c) Class works

A. Formation of quadratic equations.

Suppose ax

+ bx + c = 0 (a ≠ 0) is the required quadratic equation and α and β are the

given roots.

Then the required equation may be written as

- (sum of the roots)x + product of the roots = 0

Thus a quadratic equation can be formed when sum and product of the roots are known.

Quadratic Equations Worksheet With Answer Key Page 4