# Thread: Help on roller coaster sine function

1. ## Help on roller coaster sine function

Hi there I need help on this question.

A roller coaster takes 32 seconds to completes a circle that has a radius of 14m and is 2m off the ground. You ride in this coaster for 40 secs (5/4 times).

Find the values of a,b,c and k
y=a+bsin2pi/k(t-c)
t= time (in secs)

I tried doing it theoretically but it didn't come out right when I punched it in the graphing calculator.

2. Originally Posted by monkbear
A roller coaster takes 32 seconds to completes a circle that has a radius of 14m and is 2m off the ground. You ride in this coaster for 40 secs (5/4 times).

Find the values of a,b,c and k
y=a+bsin2pi/k(t-c)
t= time (in secs)
assuming that that the cosater car starts at the bottom of the circle and that $y$ represents the height above the ground ...

$\displaystyle y = 16 - 14\cos\left(\frac{\pi t}{16}\right)$

3. Thanks skeeter but I need the equation in sin however.
But just a quick question would this be equation be equal to yours?
16-14sin(2pi/32)(t-(-90) = y

4. Originally Posted by monkbear
Thanks skeeter but I need the equation in sin however.
But just a quick question would this be equation be equal to yours?
16-14sin(2pi/32)(t-(-90) = y
graph them both and see for yourself. also, don't mix radians and degrees.