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Completing the square and Word Problems
Question 1 (ii) Important Deleted for CBSE Board 2024 Exams
Question 1 (iii) Deleted for CBSE Board 2024 Exams
Question 1 (iv) Important Deleted for CBSE Board 2024 Exams
Question 2 (i)
Question 2 (ii)
Question 2 (iii)
Question 2 (iv) Important
Question 3 (i) Important
Question 3 (ii)
Question 4
Question 5
Question 6
Question 7 Important
Question 8 Important
Question 9 Important
Question 10 Important
Question 11
Completing the square and Word Problems
Last updated at May 29, 2023 by Teachoo
Ex 4.3 ,1 Find the roots of the following quadratic equations, if they exist, by the method of completing the square: (i) 2x2 – 7x + 3 = 0 2x2 – 7x +3 = 0 Dividing by 2 (2𝑥2 − 7𝑥 + 3 = 0)/2=0/2 2𝑥2/2 – 7𝑥/2 + 3/2=0 x2 – 7𝑥/2+3/2=0 We know that (a – b)2 = a2 – 2ab + b2 Here, a = x & – 2ab = – 7𝑥/2 – 2xb = −7𝑥/2 b = −7𝑥/(2(−2𝑥)) b = 7/4 Now, in our equation x2 −7𝑥/2+3/2=0 Adding and subtracting (7/4)^2 x2 −7𝑥/2+3/2+(7/4)^2−(7/4)^2=0 x2 +(7/4)^2−7𝑥/2+3/2−(7/4)^2=0 (𝑥− 7/4)^2+3/2 −(7/4)^2=0 (𝑥− 7/4)^2+3/2−49/16=0 (𝑥− 7/4)^2+(3(8) − 49)/16=0 (𝑥− 7/4)^2+(24 − 49)/16=0 (𝑥− 7/4)^2−25/16=0 (𝑥−7/4)^2=25/16 (𝑥−7/4)^2=(5/4)^2 Cancelling square both sides 𝑥−7/4 = ± 5/4