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10 questions from this quiz
Sum of all terms from u1u_1u1 to unu_nun
n(n+1)2\frac{n(n+1)}{2}2n(n+1)
n(n+1)(2n+1)6\frac{n(n+1)(2n+1)}{6}6n(n+1)(2n+1)
n2(n+1)24\frac{n^2(n+1)^2}{4}4n2(n+1)2
∑r3=(∑r)2\sum r^3 = \left(\sum r\right)^2∑r3=(∑r)2
When ur=f(r+1)−f(r)u_r = f(r+1) - f(r)ur=f(r+1)−f(r)
f(n+1)−f(1)f(n+1) - f(1)f(n+1)−f(1)
No, they must be memorised
Writing differences vertically
The general term
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