A Show that . 2. b Copy and complete: aligned (0 + 1)^3 &= 0^3 + 3(0)^2 + 3(0) + 1 (1…

MATHEMATICS · Multi-part · ISC · Mathematics · Algebra · Algebra

Problem

1. a Show that (x+1)3=x3+3x2+3x+1(x + 1)^3 = x^3 + 3x^2 + 3x + 1 . 2. b Copy and complete: (0+1)3=03+3(0)2+3(0)+1 (1+1)3=13+3(1)2+3(1)+1 (2+1)3=23+… (3+1)3=… ⋮ (n+1)3=…\begin{aligned} (0 + 1)^3 &= 0^3 + 3(0)^2 + 3(0) + 1 \ (1 + 1)^3 &= 1^3 + 3(1)^2 + 3(1) + 1 \ (2 + 1)^3 &= 2^3 + \dots \ (3 + 1)^3 &= \dots \ &\vdots \ (n + 1)^3 &= \dots \end{aligned} (a) Show that (x+1)3=x3+3x2+3x+1(x + 1)^3 = x^3 + 3x^2 + 3x + 1 . (b) Copy and complete: (0+1)3=03+3(0)2+3(0)+1 (1+1)3=13+3(1)2+3(1)+1 (2+1)3=23+… (3+1)3=… ⋮ (n+1)3=…\begin{aligned} (0 + 1)^3 &= 0^3 + 3(0)^2 + 3(0) + 1 \ (1 + 1)^3 &= 1^3 + 3(1)^2 + 3(1) + 1 \ (2 + 1)^3 &= 2^3 + \dots \ (3 + 1)^3 &= \dots \ &\vdots \ (n + 1)^3 &= \dots \end{aligned} (c) Add the terms vertically, and hence show that (n+1)3=3∑k=1nk2+3∑k=1nk+(n+1)(n + 1)^3 = 3 \sum_{k=1}^{n} k^2 + 3 \sum_{k=1}^{n} k + (n + 1) . (d) Given that ∑k=1nk=n(n+1)2\sum_{k=1}^{n} k = \frac{n(n + 1)}{2} , show that ∑k=1nk2=n(n+1)(2n+1)6\sum_{k=1}^{n} k^2 = \frac{n(n + 1)(2n + 1)}{6} .

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