Solving
a Quadratic Equation by Formula Method
The formula for finding roots of a quadratic equation ax2 + bx +c = 0 (derivation given in section 3.6.2) is
Solve x2 + 2x − 2 = 0 by formula method
Compare x2 + 2x − 2 = 0 with the standard form ax2 + bx +c = 0
a = 1, b = 2, c = -2
substituting the values
of a, b and c in the formula we get,
Therefore, x = −1 + √3 , −1 − √3
Solve 2x2 −
3x − 3 = 0 by formula method.
Compare 2x2 − 3x − 3 = 0 with the standard form ax2 + bx + c
= 0
substituting the values
of a, b and c in the formula we get,
Example 3.35 Solve 3p2 +
2√5p – 5 = 0 by formula method
Solution
Solution Compare 3p2
+ 2√5p – 5 = 0 with the Standard form
ax2 + bx +c = 0
a = 3, b = 2√5, c = −5 .
p = (−b ± √[b2 − 4ac]) / 2a
substituting the values of a, b and c in the
formula we get,
x = √5/3 , - √5
Solve pqx 2 − ( p +q)2 x + ( p +q)2 = 0
Solution
Compare the coefficients
of the given equation with the standard form ax 2 +
bx +c = 0
a = pq , b = −(p +q)2 , c = ( p +q)2
substituting the values of a, b and c in the formula we get,
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.