Example 9 - Chapter 4 Class 10 Quadratic Equations (Term 2)
Last updated at Aug. 3, 2021 by Teachoo
Examples
Example 1 (i)
Important
Example 1 (ii)
Example 2 Important
Example 3
Example 4
Example 5 Important
Example 6
Example 7 Deleted for CBSE Board 2022 Exams
Example 8 Important Deleted for CBSE Board 2022 Exams
Example 9 Important Deleted for CBSE Board 2022 Exams You are here
Example 10
Example 11
Example 12 Important
Example 13 (i)
Example 13 (ii) Important
Example 13 (iii)
Example 14 (i)
Example 14 (ii)
Example 15 Important
Example 16
Example 17 Important
Example 18
Chapter 4 Class 10 Quadratic Equations (Term 2)
Serial order wise
- Ex 4.1
- Ex 4.2
- Ex 4.3
- Ex 4.4
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Examples
- Case Based Questions (MCQ)
Transcript
Example 9 Find the roots of 4x2 + 3x + 5 = 0 by the method of completing the square. 4x2 + 3x + 5 = 0 Dividing by 4 4𝑥2/4+3𝑥/4+5/4=0 x2 + 3𝑥/4+5/4=0 We know that (a + b)2 = a2 + 2ab + b2 Here, a = x & 2ab = 3𝑥/4 2xb = 3𝑥/4 2b = 3/4 b = 3/4×1/2 b = 3/8 Now, in our equation x2 + 3𝑥/4+5/4=0 Adding and subtracting (3/8)^2 x2 + 3𝑥/4+5/4+(3/8)^2−(3/8)^2=0 x2 + 3𝑥/4+(3/8)^2+5/4−(3/8)^2=0 (𝑥+3/8)^2+5/4−(3/8)^2=0 (𝑥+3/8)^2=(3/8)^2−5/4 (𝑥+3/8)^2=9/64−5/4 (𝑥+3/8)^2=(9 − 5(16))/64 (𝑥+3/8)^2=(9 − 80)/64 (𝑥+3/8)^2=(−71)/64 Since square of any number cannot be negative So, answer does not exist
