Learn all Concepts of Chapter 4 Class 10 (with VIDEOS). Check - Quadratic Equations - Class 10

Last updated at Dec. 8, 2020 by Teachoo

Transcript

Ex 4.3 ,1 Find the roots of the following quadratic equations, if they exist, by the method of completing the square: (i) 2x2 โ 7x + 3 = 0 2x2 โ 7x +3 = 0 Dividing by 2 (2๐ฅ2 โ 7๐ฅ + 3 = 0)/2=0/2 2๐ฅ2/2 โ 7๐ฅ/2 + 3/2=0 x2 โ 7๐ฅ/2+3/2=0 We know that (a โ b)2 = a2 โ 2ab + b2 Here, a = x & โ 2ab = โ 7๐ฅ/2 โ 2xb = โ7๐ฅ/2 b = โ7๐ฅ/(2(โ2๐ฅ)) b = 7/4 Now, in our equation x2 โ7๐ฅ/2+3/2=0 Adding and subtracting (7/4)^2 x2 โ7๐ฅ/2+3/2+(7/4)^2โ(7/4)^2=0 x2 +(7/4)^2โ7๐ฅ/2+3/2โ(7/4)^2=0 (๐ฅโ 7/4)^2+3/2 โ(7/4)^2=0 (๐ฅโ 7/4)^2+3/2โ49/16=0 (๐ฅโ 7/4)^2+(3(8) โ 49)/16=0 (๐ฅโ 7/4)^2+(24 โ 49)/16=0 (๐ฅโ 7/4)^2โ25/16=0 (๐ฅโ7/4)^2=25/16 (๐ฅโ7/4)^2=(5/4)^2 Cancelling square both sides ๐ฅโ7/4 = ยฑ 5/4

Solving by completing square

Chapter 4 Class 10 Quadratic Equations

Concept wise

- Checking quadratic equation
- Making quadratic equation
- Solving by Splitting the middle term - Equation given
- Solving by Splitting the middle term - Statement given
- Solving by completing square
- Nature of roots
- Solving by quadratic formula - Equation given
- Solving by quadratic formula - Equation to be formed

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.