Trigonometric Functions - Confusing question

[Markd]

What equation in the form y=sin(theta)+c best models the dtat in the chart below...
____________________________________

(theta)radians : 1 : pi/2 : pi : 3pi/2 : 2pi
______________________________________
y-------------: 2 :--3--:-2-:-1----:--2
__________________________________

I am really confused on how to approach the problem, can someone please lend a hand?

 

[Jameson]

The normal sine curve goes like this:

X|0 pi/2 pi 3pi/2 2pi
Y|0 1 0 -1 0

It has a period of 2pi, meaning it takes that distance to make one cycle and then it repeats

So your graph starts at 2, then increases to 3, back to 2, down to 1, and finally back to 2.

Sound familiar?

It's just like the normal sine curve but shifted up 2 units.

-----------
y = sinx + 2

 

[cdhotfire]

I would guess you would supstitute for y and theta, but that doesn't seem to work, I also trying with a number in from of sin (theta) but that doesn't work either. Did you copy the problem correctly?

 

[Markd]

I think your right Jameson,

the period is 2pi
a value is 1
c value is 2
no phase shift

I think I am going to write it in the form y=asin(x-d)+c

so would I write, sin2pi(x)+2 or sinx+2? or does it matter?

btw, I did copy it correctly cdhotfire

 

[cdhotfire]

hehe, I wrote my response and then saw what jameson said, and i couldn't earase my awnser. :rofl:

 

[Jameson]

you'd write y = sinx + 2

the period is a separate calculation

 

[Markd]

Thanks guys