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We use summation rules to simplify our work. Read summation rules carefully; otherwise, it sounds like double talk! Note that we consistently use k as the symbol for a constant.

Rule 1: The summation of the sums of two or more variables equals the sum of their summations

i=1n(xi+yi)=i=1nxi+i=1nyi\sum\limits_{i=1}^n(x_{i}+y_{i})=\sum\limits_{i=1}^nx_{i} + \sum\limits_{i=1}^ny_{i}

Rule 2: The summation of a constant times the values of a variable is equal to the constant times the summation of the variable

i=1nkx=ki=1nx\sum\limits_{i=1}^nkx=k\sum\limits_{i=1}^nx

Rule 3: The summation of a constant taken N times is the constant times N

i=1nk=kn\sum\limits_{i=1}^nk=kn

Rule 4: The summation of the values of a variable plus a constant is equal to the summation of the values of the variable plus N times the constant

i=1n(k+x)=nk+i=1nx\sum\limits_{i=1}^n(k+x)=nk + \sum\limits_{i=1}^nx

Rule 5: The summation of the values of a variable minus a Constant is equal to the summation of the values of the variable minus N times the constant

i=1n(xk)=i=1nxnk\sum\limits_{i=1}^n(x-k)=\sum\limits_{i=1}^nx-nk

Instructions

1.

If we have

i=110i+4\sum\limits_{i=1}^{10}i+4

what do we write before the summation sign?

Assign your answer to checkpoint_1 in the code editor.

2.

If we have

i=13(i+i2)\sum\limits_{i=1}^{3}(i + i^{2})

what is the partial sum?

Assign your answer to checkpoint_2 in the code editor.

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