+118727 
+118727 Response to first answer.
y = 4-3 sin (x/4)
"The first highest point should be seven. The first lowest point should be one, correct?"
Correct except I wanted the actual points, so i want the x value as well as the y value at the highest point.
Sketch it freehand and see what you get, then check with desmos.
second response:
y = f cos (gx) -t
We are both in full agreement that the amplitude is f. So that is good. 
im going to substitute some constants to help with the other features.
let f=4, g=2 and t = 3
then you would have
y=4cos (2x) - 3
Sketch freehand, you should be able to. Then check with desmos.
| y=4cos(2x)-3 | y = f cos (gx) -t | |
| amplitude | 4 | f |
| midline | ||
| y intercept (remember this is a cos graph) | ||
| is the y intercept at the top middle or bottom? | ||
| wavelength \(\lambda\) | ||
| A maximum point | ||
| A minimum point |
By the way, I do understand that these new concepts are very hard for you. And I am happy to keep helping you to understand.
You need to understand that when you get each concept you need to practice, practice, practice, or else it will not sink in.
You can practice by making up your own similar questions, doing them yourself, and then checking your answers with Desmos.
+118727 Thanks for your lovely comments. I am very pleased to help you.
y=4-3sin(x/4) is spot on
the coefficient of x is 1/4 and
the wavelength will be 2pi / (1/4) = 8pi
I have altered your graph a little so that the x axis is in radians and I have made the step 2pi.
I have made the step equal to one quarter of the wavelgth, then it will always look nice and be easy to read from.
Here is my new graph version
https://www.desmos.com/calculator/hizjhkehuc
See if you can do this too for your future graphs.
Questions for you to answser:
NOW, without looking at the desmos graph I want you to tell me what first maximum point is.
That is worded in very lay terms ... I want the maximum point with the smallest positive x value.
And I want you to tell me what the first minimum point is too.
(These are co-ordinates with both an x and a y value)
I suggest you sketch it freehand to answer these two questions.
You can check on the desmos graph that i have just given you.
---------------
Now for y=ksin(ax)
You have treated your graph like it is fixed, it isn't, see how you can drag the a and the k into different numbers?
your graph https://www.desmos.com/calculator/g3sl7begnr
You have to pretend that k and a are just numbers and think about what that would mean.
the amplitude is given by the number that sin is multiplied by so the amplitude is 'k'
the wavelength is 2pi/ (the number in front of x, the x pronumeral)
in this case the pronumeral of x is 'a'
so the wavelenth is 2pi/a
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What about this one
y=fcos(gx) -t (where f, g and t are all positive constants.)
find
amplitude, y intercept, midline and wavelength.
