Question 2 - Solving by completing square - Chapter 4 Class 10 Quadratic Equations

Last updated at April 16, 2024 by

Example 8 - Find roots of 5x2 - 6x - 2 = 0 by completing sq - Solving by completing square

Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 2
Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 3
Example 8 - Chapter 4 Class 10 Quadratic Equations - Part 4

Transcript

Question 2 Find the roots of the equation 5x2 6x 2 = 0 by the method of completing the square. 5x2 6x 2 = 0 Dividing by 5 (5 2 6 2)/5=0/5 5 2/5 6 /5 2/5=0 x2 6 /5 2/5=0 We know that (a b)2 = a2 2ab + b2 Here, a = x & 2ab = ( 6 )/5 2xb = ( 6 )/5 2b = ( 6)/5 b = ( 6)/(5 ( 2)) b = 3/5 Now, in our equation x2 6 /5 2/5=0 Adding and subtracting (3/5)^2 x2 6 /5 2/5+(3/5)^2 (3/5)^2=0 x2 6 /5+(3/5)^2 2/5 (3/5)^2=0 ( 3/5)^2 2/5 (3/5)^2=0 ( 3/5)^2=(3/5)^2+2/5 ( 3/5)^2=9/25+2/5 ( 3/5)^2=(9 + 2(5))/25 ( 3/5)^2=(9 +10)/25 ( 3/5)^2=19/25 ( 3/5)^2=( 19)^2/5^2 Cancelling squares both sides 3/5 = 19/5 3/5 = 19/5 Solving So, x = ( (19 )+ 3)/5 and x = ( 19 + 3)/5 are the roots of the equation .

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.