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Example Questions
Example Question #171 : Trigonometry
Which of these functions fulfills these criteria?
- Amplitude of
- Period of
- -intercept of
- No phase shift
- Minimum of
Combining a good deal of our information - an amplitude of , a -intercept of and a minimum of with no phase shift - means we are looking for a cosine function. In other words, we can start right at...
We also know that because there is a period of (since when . In other words, we can conclude that the function we are looking for is...
Example Question #171 : Trigonometry
Which of these functions includes the following points?
Judging from those five given points, we can draw the following clues:
- Amplitude of
- Period of
Also, note that none of the answer choices have a phase shift, meaning that you can instantly start looking for a sine function because of the zero-rise-zero-fall-zero period that is marked by those five points. Furthermore, we can also realize that we are looking for...
...because we need a period of 4 - i.e,
when .
Example Question #173 : Trigonometry
A sine function where is time measured in seconds has the following properties:
- Amplitude of
- Minimum of
- No phase shift
- Frequency of Hz (cycles per second)
is which of these functions?
One important thing to realize is that the frequency is the reciprocal of the period. So if the function has a frequency of Hertz (or cycles per second), the period has to be or seconds. Because when , we know we are looking for a equation that includes .
Also, because we have an amplitude of but a minimum of , there must be a shift upwards by units. Only one function fulfills those two criteria and the period criteria: