HELP ME PLEASE!!!! graph each function and its inverse. after describe the domain and range of each. f(x)=(x+3)^2
@jdoe0001
do you know how to graph \(\bf x^2\quad ?\)
well i have a graphing calculator so it does it for me. i dont know how to find the inverse and the domain and range. i know when you graph x^2 you get a u shape graph
Inverse of f(x) \[ g(x)=f^{-1}(x) =\sqrt x-3 \]
so the inverse is \[\sqrt{x}-3\]
\(\begin{array}{llll} f(x)=(x&+3)^2\\ &\uparrow \\ &\textit{horizontal shift of }x^2\textit{ graph to the left by 3 units} \end{array}\)
yes
ok so how do i find the domain and range?
The domain of is all real numbers. The domain of g is all real \( x \ge 0\)
to find the inverse "relationship" of an expression, you'd just swap the variables about \(\bf f(x)=\color{red}{y}=(x+3)^2\qquad inverse\implies x=(\color{red}{y}+3)^2\\ \quad \\ \sqrt{x}=y+3\implies \sqrt{x}-3=y\) and solve for "y"
ok i dont understand the domain and range still
The domain is all x so that the function evaluated at x makes sense
The range of a function h is all the values of h(x)
the domain of a function is, all values that "x" can take, that is, the INPUT meaning, any values for "x" that produce a valid "y", not an undefined or extraneous values so for \(\bf f(x)=y=(x+3)^2\) "x" can pretty much take anything, thus \(\bf x \in \mathbb{R}\)
@jdoe0001 can help you finish this problem
for \(\bf \sqrt{x}-3=y\) the radical CANNOT be negative, because when it's negative you'd end up with an imaginary value, thus not a valid one so for \(\bf \sqrt{x}-3=y\) "x" cannot be negative, that is, has to always be either positive or 0 at the very least
ok that will work but you lost me on the last part im so confused on the values of x and them being real numbers and all that. what is xr thing
so the domain is 0 and up for the inverse?
\(\begin{array}{llll} \mathbb{R} \implies \textit{all real numbers set}\\ \quad \\ \bf x\in \mathbb{R}\implies \textit{"x" belongs to all real numbers set} \end{array}\)
0 and up, yes, I assume you've covered "imaginary numbers", so when you have a negative radicand, that's what you've got
yes. so after that how do you find the range of the two functions
..... well... notice your graph in the calculator for \(\bf f(x)=(x+3)^2\) what's its vertex?
the vertex is -3??? i think
-3? x= -3? y = -3?
what's the (x,y) pair for the vertex?
oh i forgot to put it in that form it is (-3,0)
does the graph go below (-3, 0)? no, since that's the vertex, meaning that "y" values don't go pass 0, they do go ABOVE 0, not BELOW 0 so that's the range range= values for "y"
you can also try graphing maybe \(\bf y=\sqrt{x}-3\) and you'll also see the range as well, by just looking at the graph
so both x and y are values greater than or equal to 0 correct
is that the domain and range for both functions?
well.... for \(\bf f(x)=y=(x+3)^2\) the values for "y" don't go pass the vertex of (-3, 0) so the range goes ABOVE 0, not BELOW 0, that'd be the range for that one recall that for "x" or the domain was \(\bf x \in \mathbb{R}\)
"so the range goes ABOVE 0, not BELOW 0" <---- so, what does that make the range?
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