diff --git a/_subfiles/_def-cond-expectation.qmd b/_subfiles/_def-cond-expectation.qmd index 56865221f..9cd199322 100644 --- a/_subfiles/_def-cond-expectation.qmd +++ b/_subfiles/_def-cond-expectation.qmd @@ -677,7 +677,7 @@ $$ \\&= \sum_{y \in \rangef{Y}} \paren{a h_1(x, y) + b h_2(x, y)} \cd \P(Y = y \mid X = x) && \text{(definition of conditional expectation)} \\ &= a \sum_{y \in \rangef{Y}} h_1(x, y) \cd \P(Y = y \mid X = x) + b \sum_{y \in \rangef{Y}} h_2(x, y) \cd \P(Y = y \mid X = x) -&& \text{(split the sum; factor out the constants)} \\ +&& \text{(distribute the sum over the terms; factor out the constants)} \\ &= a\E{h_1(X, Y) \mid X = x} + b\E{h_2(X, Y) \mid X = x} && \text{(definition of conditional expectation)} \ea diff --git a/_subfiles/_exr-fubini-joint-disc-infinite.qmd b/_subfiles/_exr-fubini-joint-disc-infinite.qmd index 80301d0b4..42b91cd84 100644 --- a/_subfiles/_exr-fubini-joint-disc-infinite.qmd +++ b/_subfiles/_exr-fubini-joint-disc-infinite.qmd @@ -67,7 +67,7 @@ $$ \\&= \sum_{x=0}^{\infty} p^x \sb{x(1-p) + p} && \text{(multiply } (1-p)^2 \text{ into the parentheses)} \\&= (1-p) \sum_{x=0}^{\infty} x\,p^x + p \sum_{x=0}^{\infty} p^x -&& \text{(split the sum; factor out the constants)} +&& \text{(distribute the sum over the terms; factor out the constants)} \\&= (1-p) \cd \frac{p}{(1-p)^2} + p \cd \frac{1}{1-p} && \text{(geometric-series facts)} \\&= \frac{p}{1-p} + \frac{p}{1-p} diff --git a/_subfiles/_exr-fubini-joint-mixed-infinite.qmd b/_subfiles/_exr-fubini-joint-mixed-infinite.qmd index 79affb2a1..b1a8bad5d 100644 --- a/_subfiles/_exr-fubini-joint-mixed-infinite.qmd +++ b/_subfiles/_exr-fubini-joint-mixed-infinite.qmd @@ -46,7 +46,7 @@ $$ \\&= \frac{1-q}{2} \sum_{y=0}^{\infty} (y+1)\,q^y && \text{(cancel } y + 1 \text{; factor out } \tfrac{1-q}{2} \text{)} \\&= \frac{1-q}{2} \paren{\sum_{y=0}^{\infty} y\,q^y + \sum_{y=0}^{\infty} q^y} -&& \text{(split the sum)} +&& \text{(distribute the sum over the terms)} \\&= \frac{1-q}{2} \paren{\frac{q}{(1-q)^2} + \frac{1}{1-q}} && \text{(geometric-series facts)} \\&= \frac{1-q}{2} \cd \frac{q + (1-q)}{(1-q)^2} diff --git a/_subfiles/_sol-linearity-use.qmd b/_subfiles/_sol-linearity-use.qmd index 54e9072f0..fcd8458ec 100644 --- a/_subfiles/_sol-linearity-use.qmd +++ b/_subfiles/_sol-linearity-use.qmd @@ -1,6 +1,6 @@ ::: {#sol-linearity-use} -Pull the constant $1/n$ out and split the sum, both by @thm-linearity-expectation: +Pull the constant $1/n$ out and distribute the sum over the terms, both by @thm-linearity-expectation: $$ \begin{aligned} diff --git a/_subfiles/_thm-lotus.qmd b/_subfiles/_thm-lotus.qmd index 5b7f8edd7..463facc77 100644 --- a/_subfiles/_thm-lotus.qmd +++ b/_subfiles/_thm-lotus.qmd @@ -130,7 +130,7 @@ $$ &= a\sum_{x \in \rangef{X}}\sum_{y \in \rangef{Y}} x \cd \P(X=x, Y=y) + b\sum_{x \in \rangef{X}}\sum_{y \in \rangef{Y}} y \cd \P(X=x, Y=y) + c\sum_{x \in \rangef{X}}\sum_{y \in \rangef{Y}} \P(X=x, Y=y) -&& \text{(split the sum; constants factor out)}\\ +&& \text{(distribute the sum over the terms; constants factor out)}\\ &= a\sum_{x \in \rangef{X}}\sum_{y \in \rangef{Y}} x \cd \P(X=x, Y=y) + b\sum_{y \in \rangef{Y}}\sum_{x \in \rangef{X}} y \cd \P(X=x, Y=y) + c\sum_{x \in \rangef{X}}\sum_{y \in \rangef{Y}} \P(X=x, Y=y)