trig function application

[Clifford]

p(t)=20sin2pit + 100 is a function that models a humans blood pressure when resting where p(t) is the blood pressure in millimertres of mecrury and t is time in seconds.
sketch a graph of this function for 0 <= t <= 3.
Find the period of this function and describe what it represents.

For the graph of this function I subbed:
t = 0 in and got 100,
t = 1 in and got 102,
t = 2 in and got 104,
t = 3 in and got 106
and I just graphed these three 4 points.

For the period, you find it by the equation y = sin bx, where b is the period
a normal sine graph has a period of 2pi. In p(t)=20sin2pit + 100, would the 'b' value by 2, leaving you with a period of just pi? I am not sure what the period represents.

 

[jwpaine]

\(\displaystyle \L p(t)=20 \cdot sin(2\pi \cdot t) + 100\)

Period of function is \(\displaystyle \L \frac{2\pi}{b} = \frac{2\pi}{2\pi} = 1\)


John.

 

[morson]

I am not sure what the period represents.

The constant distance between x-intercepts. If the distance is constant for each distance, the function is periodic. If you take a look at somebody's brain waves while they're awake on an EEG, the waves will have a small period (though it's not technically periodic), and a high frequency.