<< Chapter < Page Chapter >> Page >

Shifts of the parent function f ( x ) = b x

For any constants c and d , the function f ( x ) = b x + c + d shifts the parent function f ( x ) = b x

  • vertically d units, in the same direction of the sign of d .
  • horizontally c units, in the opposite direction of the sign of c .
  • The y -intercept becomes ( 0 , b c + d ) .
  • The horizontal asymptote becomes y = d .
  • The range becomes ( d , ) .
  • The domain, ( , ) , remains unchanged.

Given an exponential function with the form f ( x ) = b x + c + d , graph the translation.

  1. Draw the horizontal asymptote y = d .
  2. Identify the shift as ( c , d ) . Shift the graph of f ( x ) = b x left c units if c is positive, and right c units if c is negative.
  3. Shift the graph of f ( x ) = b x up d units if d is positive, and down d units if d is negative.
  4. State the domain, ( , ) , the range, ( d , ) , and the horizontal asymptote y = d .

Graphing a shift of an exponential function

Graph f ( x ) = 2 x + 1 3. State the domain, range, and asymptote.

We have an exponential equation of the form f ( x ) = b x + c + d , with b = 2 , c = 1 , and d = 3.

Draw the horizontal asymptote y = d , so draw y = −3.

Identify the shift as ( c , d ) , so the shift is ( 1 , −3 ) .

Shift the graph of f ( x ) = b x left 1 units and down 3 units.

Graph of the function, f(x) = 2^(x+1)-3, with an asymptote at y=-3. Labeled points in the graph are (-1, -2), (0, -1), and (1, 1).

The domain is ( , ) ; the range is ( 3 , ) ; the horizontal asymptote is y = −3.

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Graph f ( x ) = 2 x 1 + 3. State domain, range, and asymptote.

The domain is ( , ) ; the range is ( 3 , ) ; the horizontal asymptote is y = 3.

Graph of the function, f(x) = 2^(x-1)+3, with an asymptote at y=3. Labeled points in the graph are (-1, 3.25), (0, 3.5), and (1, 4).
Got questions? Get instant answers now!

Given an equation of the form f ( x ) = b x + c + d for x , use a graphing calculator to approximate the solution.

  • Press [Y=] . Enter the given exponential equation in the line headed “ Y 1 = ”.
  • Enter the given value for f ( x ) in the line headed “ Y 2 = ”.
  • Press [WINDOW] . Adjust the y -axis so that it includes the value entered for “ Y 2 = ”.
  • Press [GRAPH] to observe the graph of the exponential function along with the line for the specified value of f ( x ) .
  • To find the value of x , we compute the point of intersection. Press [2ND] then [CALC] . Select “intersect” and press [ENTER] three times. The point of intersection gives the value of x for the indicated value of the function.

Approximating the solution of an exponential equation

Solve 42 = 1.2 ( 5 ) x + 2.8 graphically. Round to the nearest thousandth.

Press [Y=] and enter 1.2 ( 5 ) x + 2.8 next to Y 1 =. Then enter 42 next to Y2= . For a window, use the values –3 to 3 for x and –5 to 55 for y . Press [GRAPH] . The graphs should intersect somewhere near x = 2.

For a better approximation, press [2ND] then [CALC] . Select [5: intersect] and press [ENTER] three times. The x -coordinate of the point of intersection is displayed as 2.1661943. (Your answer may be different if you use a different window or use a different value for Guess? ) To the nearest thousandth, x 2.166.

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Solve 4 = 7.85 ( 1.15 ) x 2.27 graphically. Round to the nearest thousandth.

x 1.608

Got questions? Get instant answers now!

Graphing a stretch or compression

While horizontal and vertical shifts involve adding constants to the input or to the function itself, a stretch or compression occurs when we multiply the parent function f ( x ) = b x by a constant | a | > 0. For example, if we begin by graphing the parent function f ( x ) = 2 x , we can then graph the stretch, using a = 3 , to get g ( x ) = 3 ( 2 ) x as shown on the left in [link] , and the compression, using a = 1 3 , to get h ( x ) = 1 3 ( 2 ) x as shown on the right in [link] .

Questions & Answers

how to study physic and understand
Ewa Reply
what is conservative force with examples
Moses
what is work
Fredrick Reply
the transfer of energy by a force that causes an object to be displaced; the product of the component of the force in the direction of the displacement and the magnitude of the displacement
AI-Robot
why is it from light to gravity
Esther Reply
difference between model and theory
Esther
Is the ship moving at a constant velocity?
Kamogelo Reply
The full note of modern physics
aluet Reply
introduction to applications of nuclear physics
aluet Reply
the explanation is not in full details
Moses Reply
I need more explanation or all about kinematics
Moses
yes
zephaniah
I need more explanation or all about nuclear physics
aluet
Show that the equal masses particles emarge from collision at right angle by making explicit used of fact that momentum is a vector quantity
Muhammad Reply
yh
Isaac
A wave is described by the function D(x,t)=(1.6cm) sin[(1.2cm^-1(x+6.8cm/st] what are:a.Amplitude b. wavelength c. wave number d. frequency e. period f. velocity of speed.
Majok Reply
what is frontier of physics
Somto Reply
A body is projected upward at an angle 45° 18minutes with the horizontal with an initial speed of 40km per second. In hoe many seconds will the body reach the ground then how far from the point of projection will it strike. At what angle will the horizontal will strike
Gufraan Reply
Suppose hydrogen and oxygen are diffusing through air. A small amount of each is released simultaneously. How much time passes before the hydrogen is 1.00 s ahead of the oxygen? Such differences in arrival times are used as an analytical tool in gas chromatography.
Ezekiel Reply
please explain
Samuel
what's the definition of physics
Mobolaji Reply
what is physics
Nangun Reply
the science concerned with describing the interactions of energy, matter, space, and time; it is especially interested in what fundamental mechanisms underlie every phenomenon
AI-Robot
what is isotopes
Nangun Reply
nuclei having the same Z and different N s
AI-Robot
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, College algebra. OpenStax CNX. Feb 06, 2015 Download for free at https://legacy.cnx.org/content/col11759/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'College algebra' conversation and receive update notifications?

Ask