Q. Which is the graph of \(g(x)=\left(\tfrac{1}{2}\right)^{x+3}-4\)?
Answer
Combine terms. We have
\[ g(x)=\frac{1}{2}x+3-4=\frac{1}{2}x-1. \]
Therefore the graph is a straight line with slope \(\tfrac{1}{2}\) and y‑intercept \(-1\); it passes through the points \((0,-1)\), \((2,0)\), and \((4,1)\).
\[ \boxed{g(x)=\tfrac{1}{2}x-1} \]
Detailed Explanation
Problem: Analyze and graphically describe the function \( g(x)=\bigl(\tfrac{1}{2}\bigr)^{x+3}-4 \).
Step 1 — Parent function
The exponential base is \( \tfrac{1}{2} \), so the parent function is
\[
f(x)=\bigl(\tfrac{1}{2}\bigr)^{x},
\]
which is an exponential decay function (values decrease as \(x\) increases).
Step 2 — Horizontal shift
The exponent is \(x+3\). Write
\[
x+3=x-(-3),
\]
so the graph of the parent function is shifted 3 units to the left. Equivalently,
\[
g(x)=f(x+3)-4.
\]
Step 3 — Vertical shift and horizontal asymptote
The constant \(-4\) outside the exponential shifts the graph 4 units downward. The parent function has horizontal asymptote \(y=0\); after the vertical shift the asymptote becomes
\[
y=-4.
\]
Step 4 — y-intercept
Set \(x=0\):
\[
g(0)=\bigl(\tfrac{1}{2}\bigr)^{0+3}-4=\bigl(\tfrac{1}{2}\bigr)^{3}-4=\tfrac{1}{8}-4=-\tfrac{31}{8}=-3.875.
\]
Thus the y-intercept is \((0,-\tfrac{31}{8})\).
Step 5 — x-intercept
Set \(g(x)=0\) and solve:
\[
0=\bigl(\tfrac{1}{2}\bigr)^{x+3}-4
\quad\Rightarrow\quad
\bigl(\tfrac{1}{2}\bigr)^{x+3}=4.
\]
Write both sides with base \(2\):
\[
(2^{-1})^{x+3}=2^{2}\quad\Longrightarrow\quad 2^{-(x+3)}=2^{2}.
\]
Equating exponents gives
\[
-(x+3)=2 \quad\Rightarrow\quad x+3=-2 \quad\Rightarrow\quad x=-5.
\]
So the x-intercept is \((-5,0)\).
Summary
\[
g(x)=\bigl(\tfrac{1}{2}\bigr)^{x+3}-4
\]
is an exponential decay curve obtained from \(f(x)=\bigl(\tfrac{1}{2}\bigr)^{x}\) by shifting 3 units left and 4 units down. Its horizontal asymptote is \(y=-4\), the x-intercept is \((-5,0)\), and the y-intercept is \((0,-\tfrac{31}{8})\).
Graph
FAQs
What is the simplified form of the function g(x)?
What are the slope and y-intercept of ( g(x) )?
How do I sketch the graph quickly?
What is the x-intercept of ( g(x) )?
What are the domain and range of ( g(x) )?
How can I get more points to plot?
How does this graph relate to ( y=tfrac{1}{2}x )?
Which lines are parallel or perpendicular to ( g(x) )?
Pick what fits you.
Math, Calculus, Geometry, etc.