A function $f(x)$ starts out at x = 0 with a value of $7.9$ and goes up at constant rate of $0.3$ units on the $y$-axis for each unit on the $x$-axis. Give a formula for this function and plot it.
Give a formula for $f(x)$ that starts at $x = 0$ and grows at constant rate of $0.3$
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linear-algebra
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4Here is a hint to get you started: since the function increases at a constant rate, it is linear, so it is of the form $f(x)=ax+b$. – 2017-02-02
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1$f(x)=mx+h$, $f(0)=7.9$, $m=0.3/1$ – 2017-02-02
2 Answers
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$$f(x)=0.3\cdot x +b$$
Now find $b$ using $f(0)=7.9$
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As @Dave said, your function increases at a constant rate of .3 units and $f(0)=7.9$. All linear functions can be expressed in the form $f(x)=mx+b$, where $m$ is the slope and $b$ is the y-intercept. Your slope is $.3$, because it rises $.3$ units for every $1$ unit that it runs. Your y-intercept will be 7.9, because the function is $7.9$ when $x=0$.
Plugging these into the formula provided above ($m=.3$ and $b=7.9$)
$f(x)=.3x+7.9$
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0a linear function has a form $f(x)=mx$ and not $f(x)=mx+b$ – 2017-02-02