What is the formula for the sum of the cubes of the first $n$ natural numbers??
$$ \sum^{n}_{r=1} r^3 = \frac{1}{4}n^2(n+1)^2 $$
How could you rewrite $\sum^{n}_{r=1} r^3$??
$$ \frac{1}{4}n^2(n+1)^2 $$
What’s another way of expressing $\frac{1}{4}n^2(n+1)^2$??
$$ \sum^{n}_{r=1} r^3 $$
How could you rewrite $\sum^{n}_{r=1} 4r^2$??
$$ n^2(n+1)^2 $$
What’s an easy way for remembering the sum of cubes formula??
It’s the sum of the natural numbers formula squared.
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date: 2020-09-16 17:57
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title: Further Maths - Sums of Cubes