the amplitude is (max -min)/2 = 13-1/2=6

is b=2pi/period , the period seems to be about 6, so b=pi/3

c = horizontal shift(I doesn't seem to be a horizontal shift). How do I calculate it?

d= (max+min)/2 = 13 + 1/2=14/2=7

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- Dec 16th 2010, 03:00 PMterminatorsinusoidal function
the amplitude is (max -min)/2 = 13-1/2=6

is b=2pi/period , the period seems to be about 6, so b=pi/3

c = horizontal shift(I doesn't seem to be a horizontal shift). How do I calculate it?

d= (max+min)/2 = 13 + 1/2=14/2=7 - Dec 16th 2010, 04:04 PMSudharaka
Dear terminator,

According to the details you have found,

$\displaystyle y=6\sin\{\frac{\pi}{3}\left(x+c\right)\}+7$

When $\displaystyle x=0\Rightarrow y=7$

$\displaystyle 7=6\sin\{\frac{\pi}{3}\left(c\right)\}+7\Rightarro w \dfrac{\pi c}{3}=n\pi~where~n\in Z$

$\displaystyle c=3n~where~n\in Z$

Hope this will help you. - Dec 16th 2010, 08:00 PMSammyS

It's also true that $\displaystyle \displaystyle y'>0$ at $\displaystyle \displaystyle x=0$

so, $\displaystyle \displaystyle {{\pi c}\over{3}}\approx 2\pi n$.

Thus: $\displaystyle \displaystyle c\approx 6 n$.

Since the simplest case of $\displaystyle \displaystyle c\approx 6 n$ is when $\displaystyle \displaystyle n=0$, I would choose $\displaystyle \displaystyle c\approx 0\ .$

Also, it looks like the period is closer to 6.2 than it is to 6, (BTW: That's very close to $\displaystyle \displaystyle 2\pi\ .$) so I would say that $\displaystyle \displaystyle b\approx {{\pi}\over{3.1}}\ ,$ maybe even $\displaystyle \displaystyle b\approx 1\ .$