
Ex 4.3
Ex 4.3, 1 (ii) Important Deleted for CBSE Board 2022 Exams
Ex 4.3, 1 (iii) Deleted for CBSE Board 2022 Exams
Ex 4.3, 1 (iv) Important Deleted for CBSE Board 2022 Exams You are here
Ex 4.3, 2 (i)
Ex 4.3, 2 (ii)
Ex 4.3, 2 (iii)
Ex 4.3, 2 (iv) Important
Ex 4.3, 3 (i) Important
Ex 4.3, 3 (ii)
Ex 4.3, 4
Ex 4.3, 5
Ex 4.3, 6
Ex 4.3, 7 Important
Ex 4.3, 8 Important
Ex 4.3, 9 Important
Ex 4.3, 10 Important
Ex 4.3, 11
Last updated at Aug. 3, 2021 by Teachoo
Ex 4.3 ,1 Find the roots of the following quadratic equations, if they exist, by the method of completing the square: (iv) 2x2 + x + 4 = 0 2x2 + x + 4 = 0 Dividing equation by 2 (2𝑥2 + 𝑥 + 4)/2=0/2 2𝑥2/2+𝑥/2 + 4/2=0 x2 + 𝑥/2+2=0 We know that (a + b)2 = a2 + 2ab + b2 Here, a = x & 2ab = 𝑥/2 2xb = 𝑥/2 2b = 1/2 b = 1/2×1/2 b = 1/4 Now, in our equation x2 + 𝑥/2+2=0 Adding and subtracting (1/4)^2 x2 + 𝑥/2 +2+(1/4)^2−(1/4)^2=0 "x2 + " 𝑥/2+(1/4)^2+2−(1/4)^2=0 (𝑥+1/4)^2+2−(1/4)^2=0 (𝑥+1/4)^2+2−1/16=0 (𝑥+1/4)^2+((32 − 1)/16)=0 (𝑥+1/4)^2+ 31/16=0 (𝑥+1/4)^2=(−31)/16 Since square of any number cannot be negative So, answer does not exist