How do you find the range and intercepts of the function f(x)=4|x+5| ?
The range is the set of all possible outputs that a function can produce.
f(x)=4|x+5|
The absolute value of any number will can result in a positive number or 0, and 4 multiplied by a positive number or 0 does not change this property at all. Therefore, the range is the following:
Range:{R|y≥0}
This means that the range can be all nonnegative numbers. In interval notation, it would look like the following:
Range:[0,+∞)
How do we find the intercepts? To do it without a graph, you can figure out by setting x=0 and y=0 and solving in each case. Let's do that.
y=4|x+5| | Plug in 0 for x. This time, we are solving for the y-intercept. |
y=4|0+5| | Simplify inside the absolute value first. |
y=4|5| | |
y=4∗5=20 | We have now determined the coordinates of the y-intercept. |
(0,20) | This is the exact coordinates of the y-intercept. |
Let's do the exact same process. This time, however, we set y=0 to find the x-intecept.
y=4|x+5| | Set y equal to 0. |
0=4|x+5| | Divide by 4 on both sides. |
0=|x+5| | The absolute value always splits an equation into its plus or minus. However, 0 is neither positive nor negative, so there aren't 2 equations that one can set up. |
x+5=0 | |
x=−5 | We have now determined the x-intercept, as well. |
(−5,0) | |
The range is the set of all possible outputs that a function can produce.
f(x)=4|x+5|
The absolute value of any number will can result in a positive number or 0, and 4 multiplied by a positive number or 0 does not change this property at all. Therefore, the range is the following:
Range:{R|y≥0}
This means that the range can be all nonnegative numbers. In interval notation, it would look like the following:
Range:[0,+∞)
How do we find the intercepts? To do it without a graph, you can figure out by setting x=0 and y=0 and solving in each case. Let's do that.
y=4|x+5| | Plug in 0 for x. This time, we are solving for the y-intercept. |
y=4|0+5| | Simplify inside the absolute value first. |
y=4|5| | |
y=4∗5=20 | We have now determined the coordinates of the y-intercept. |
(0,20) | This is the exact coordinates of the y-intercept. |
Let's do the exact same process. This time, however, we set y=0 to find the x-intecept.
y=4|x+5| | Set y equal to 0. |
0=4|x+5| | Divide by 4 on both sides. |
0=|x+5| | The absolute value always splits an equation into its plus or minus. However, 0 is neither positive nor negative, so there aren't 2 equations that one can set up. |
x+5=0 | |
x=−5 | We have now determined the x-intercept, as well. |
(−5,0) | |