In Grade 10, you studied graphs of many different forms. In this chapter, you will learn a little more about the graphs of exponential functions.
Functions of the form
$y=a{b}^{(x+p)}+q$ For
$b>0$
This form of the exponential function is slightly more complex than the form studied in Grade 10.
Investigation : functions of the form
$y=a{b}^{(x+p)}+q$
On the same set of axes, with
-5\le x\le 3 and
-35\le y\le 35 , plot the following graphs:
$f\left(x\right)=-2\xb7{2}^{(x+1)}+1$
$g\left(x\right)=-1\xb7{2}^{(x+1)}+1$
$h\left(x\right)=0\xb7{2}^{(x+1)}+1$
$j\left(x\right)=1\xb7{2}^{(x+1)}+1$
$k\left(x\right)=2\xb7{2}^{(x+1)}+1$
Use your results to understand what happens when you change the value of
$a$ .
You should find that the value of
$a$ affects whether the graph curves upwards (
$a>0$ ) or curves downwards (
$a<0$ ). You should also find that a larger value of
$a$ (when
$a$ is positive) stretches the graph upwards. However, when
$a$ is negative, a lower value of
$a$ (such as -2 instead of -1) stretches the graph downwards. Finally, note that when
$a=0$ the graph is simply a horizontal line. This is why we set
$a\ne 0$ in the original definition of these functions.
On the same set of axes, with
-3\le x\le 3 and
-5\le y\le 20 , plot the following graphs:
$f\left(x\right)=1\xb7{2}^{(x+1)}-2$
$g\left(x\right)=1\xb7{2}^{(x+1)}-1$
$h\left(x\right)=1\xb7{2}^{(x+1)}+0$
$j\left(x\right)=1\xb7{2}^{(x+1)}+1$
$k\left(x\right)=1\xb7{2}^{(x+1)}+2$
Use your results to understand what happens when you change the value of
$q$ .
You should find that when
$q$ is increased, the whole graph is translated (moved) upwards. When
$q$ is decreased (poosibly even made negative), the graph is translated downwards.
On the same set of axes, with
-5\le x\le 3 and
-35\le y\le 35 , plot the following graphs:
$f\left(x\right)=-2\xb7{2}^{(x+1)}+1$
$g\left(x\right)=-1\xb7{2}^{(x+1)}+1$
$h\left(x\right)=0\xb7{2}^{(x+1)}+1$
$j\left(x\right)=1\xb7{2}^{(x+1)}+1$
$k\left(x\right)=2\xb7{2}^{(x+1)}+1$
Use your results to understand what happens when you change the value of
$a$ .
You should find that the value of
$a$ affects whether the graph curves upwards (
$a>0$ ) or curves downwards (
$a<0$ ). You should also find that a larger value of
$a$ (when
$a$ is positive) stretches the graph upwards. However, when
$a$ is negative, a lower value of
$a$ (such as -2 instead of -1) stretches the graph downwards. Finally, note that when
$a=0$ the graph is simply a horizontal line. This is why we set
$a\ne 0$ in the original definition of these functions.
Following the general method of the above activities, choose your own values of
$a$ and
$q$ to plot 5 graphs of
$y=a{b}^{(x+p)}+q$ on the same set of axes (choose your own limits for
$x$ and
$y$ carefully). Make sure that you use the same values of
$a$ ,
$b$ and
$q$ for each graph, and different values of
$p$ . Use your results to understand the effect of changing the value of
$p$ .
These different properties are summarised in
[link] .
Table summarising general shapes and positions of functions of the form
$y=a{b}^{(x+p)}+q$ .
$p<0$
$p>0$
$a>0$
$a<0$
$a>0$
$a<0$
$q>0$
$q<0$
Domain and range
For
$y=a{b}^{(x+p)}+q$ , the function is defined for all real values of
$x$ . Therefore, the domain is
$\{x:x\in \mathbb{R}\}$ .
The range of
$y=a{b}^{(x+p)}+q$ is dependent on the sign of
$a$ .
Therefore, if
$a>0$ , then the range is
$\left\{f\right(x):f(x)\in [q,\infty \left)\right\}$ . In other words
$f\left(x\right)$ can be any real number greater than
$q$ .
If potatoes cost Jane $1 per kilogram and she has $5 that could possibly spend on potatoes or other items. If she feels that the first kilogram of potatoes is worth $1.50, the second kilogram is worth$1.14, the third is worth $1.05 and subsequent kilograms are worth $0.30, how many kilograms of potatoes will she purchase? What if she only had $2 to spend?
QI: (A) Asume the following cost data are for a purely competitive producer:
At a product price Of $56. will this firm produce in the short run? Why Why not? If it is preferable to produce, what will be the profit-maximizing Or loss-minimizing Output?
Explain. What economic profit or loss will the
it is the quantity of commodities that consumers are willing and able to purchase at particular prices and at a given time
Munanag
quantity of commodities dgat consumers are willing to pat at particular price
Omed
demand depends upon 2 things 1wish to buy 2 have purchasing power of that deserving commodity except any from both can't be said demand.
Bashir
Demand is a various quantity of a commodities that a consumer is willing and able to buy at a particular price within a given period of time. All other things been equal.
Vedzi
State the law of demand
Vedzi
The desire to get something is called demand.
Mahabuba
what is the use of something should pay for its opportunity foregone to indicate?
Researchers demonstrated that the hippocampus functions in memory processing by creating lesions in the hippocampi of rats, which resulted in ________.