Give some Algebraic Identities.
Answers
Give some Algebraic Identities.
(i) (a+b)(a-b) = a²-b²
(ii) (a+b)² = a²+2ab+b² = (a-b)²+4ab
(iii) (a-b)² = a²-2ab+b² =(a²+b²+2ab)-4ab= (a+b)²-4ab
(iv) (a²-b²) = (a-b)(a+b)
(v) (a+b)³ = a³+b³+3a²b+3ab² = a³+b³+3ab(a+b)
(vi) (a-b)³ = a³-b³-3a²b+3ab² = a³-b³-3ab(a-b)
(vii) a³+b³ = (a+b)(a²+b²-ab) = (a+b)³-3ab(a+b)
(viii)a³-b³ = (a-b) (a²+b²+ab) = (a-b)³-3ab(a+b)
(ix) (a+b+c)² = a²+b²+c²+2ab+2bc+2ca = a²+b²+c²+2(ab+bc+ac)
(x) a²+b²+c² = (a+b+c)²-2(ab+bc+ac)
(xi) (a+b+c)³ = a³+b³+c³+3(a+b)(b+c)(c+a)
(xii) a³+b³+c³-3abc = (a+b+c)(a²+b²+c²-ab-bc-ac)
Some Standard Algebraic Identities list are given below:
Identity I: (a + b)2 = a2 + 2ab + b2
Identity III: a2 – b2= (a + b)(a – b)
Identity IV: (x + a)(x + b) = x2 + (a + b) x + ab.
Identity V: (a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca.
Identity VI: (a + b)3 = a3 + b3 + 3ab (a + b)