Ex 2.5

Ex 2.5, 1 (i)

Ex 2.5, 1 (ii)

Ex 2.5, 1 (iii) Important

Ex 2.5, 1 (iv)

Ex 2.5, 1 (v)

Ex 2.5, 2 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 2 (ii) Important

Ex 2.5, 2 (iii)

Ex 2.5, 3 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 3 (ii) Important

Ex 2.5, 3 (iii)

Ex 2.5, 4 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 4 (ii)

Ex 2.5, 4 (iii) Important

Ex 2.5, 4 (iv)

Ex 2.5, 4 (v)

Ex 2.5, 4 (vi)

Ex 2.5, 5 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 5 (ii) Important

Ex 2.5, 6 (i)

Ex 2.5, 6 (ii)

Ex 2.5, 6 (iii)

Ex 2.5, 6 (iv) Important

Ex 2.5, 7 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 7 (ii)

Ex 2.5, 7 (iii) Important

Ex 2.5, 8 (i)

Ex 2.5, 8 (ii)

Ex 2.5, 8 (iii) Important

Ex 2.5, 8 (iv) Important

Ex 2.5, 8 (v)

Ex 2.5, 9 (i)

Ex 2.5, 9 (ii)

Ex 2.5, 10 (i) Important Deleted for CBSE Board 2023 Exams

Ex 2.5, 10 (ii)

Ex 2.5, 11 Deleted for CBSE Board 2023 Exams

Ex 2.5,12 Important You are here

Ex 2.5,13

Ex 2.5, 14 (i)

Ex 2.5, 14 (ii) Important

Ex 2.5, 15 (i)

Ex 2.5, 15 (ii) Important

Ex 2.5, 16 (i) Deleted for CBSE Board 2023 Exams

Ex 2.5, 16 (ii) Important

Last updated at Aug. 25, 2021 by Teachoo

Ex 2.5, 12 Verify that x3 + y3 + z3 – 3xyz = 1/2 (x + y + z)[(x – y)2 + (y – z)2 + (z – x)2] Solving R.H.S 1/2 (x + y + z)[(x – y)2 + (y – z)2 + (z – x)2] Using (a - b)2 = a2 + b2 - 2ab = 1/2 (x + y + z) [ (x2 + y2 – 2xy) + (y2 + z2 – 2yz) + (z2 + x2 – 2zx)] = 1/2 (x + y + z) [2x2 + 2y2 + 2z2 – 2xy– 2yz – 2zx] = 1/2 (x + y + z) 2 [x2 + y2 + z2 – xy – yz – zx] = (x + y + z) [x2 + y2 + z2 – xy – yz – zx] We know x3 + y3 + z3 – 3xyz = (x + y + z) (x2 + y2 + z2 – xy – yz – zx) = x3 + y3 + z3 – 3xyz = L.H.S