Electrical Engineering maths help with Desmos graphing calculator

I am struggling with a question on my electrical engineering course. The question requires me to 'draw at least two cycles of this signal and annotate the drawing so that your non-technical colleagues may understand the relevant information it contains. It asks me to use the graphing calculator Desmos | Graphing Calculator.

the question is as follows...

one of your labratory instantaneous test signal voltages (Vs) is described by the equation....

Vs = 8sin (2 π f t - ( π / 4)

where f=500kHz and t represents time.

Make t the subject and hence determine the first point in time when the instantaneous signal voltage has a magnitude of +5v.

I have ended up with...

t = (sin^-1(5/8)+ π/4) / 2 π f

f = 5 x 10^5

I then get 4.649005 x10^-7

I am now unsure how to input this in to the graphing calculator?!

Any help would be much appreciated.

Thanks

If you click on the "tv arrow" in the top right, you get an url which you can post.
But you need to plot the t-Vs sinusoidal curve and the Vs=5, neither of which youve done / or explained what youve tried to do.

You could start by plotting a simple sinusoidal curve
Vs = sin(t)
and take it from there.

I think I'm out of my depth here! I've never used a graphing calculator before so no idea what figures to put where and in what format. I've got a meeting arranged with a tutor in a few weeks so hopefully they can show me how to use the graphing calculator then.

thanks for your help

I think I'm out of my depth here! I've never used a graphing calculator before so no idea what figures to put where and in what format. I've got a meeting arranged with a tutor in a few weeks so hopefully they can show me how to use the graphing calculator then.

thanks for your help

Hello

I am stuck on the same part of this question. Did you manage to figure out how to draw the two cycles?

Have you tried using desmos and doing a basic sin graph as a start? You can post your attempt using the "Share Graph" button in the top right of desmos

Hello

I am stuck on the same part of this question. Did you manage to figure out how to draw the two cycles?

Hi,

Think I cracked it. I put...

y = 8sin (2 π f x - ( π / 4)

In the the left hand panel. You have to replace f with the figure given for the frequency (make sure its in Hz not kHz).
This should produce a sinewave. I took 2 cycles to mean zoom to an extent on the graph that shows 2 full complete cycles of the sinewave.

Hope that helps!

Hello

https://www.desmos.com/calculator/olh25pm4og

Does this look similar to your sine wave?

Thanks

I think i have done it correctly now.

https://www.desmos.com/calculator/8fj1tbrhl1

Did you add notes explaining the sine wave?

Appreciate your help.

I think i have done it correctly now.

https://www.desmos.com/calculator/8fj1tbrhl1

Did you add notes explaining the sine wave?

Appreciate your help.

Hi,

Think I cracked it. I put...

y = 8sin (2 π f x - π / 4)

In the the left hand panel. You have to replace f with the figure given for the frequency (make sure its in Hz not kHz).
This should produce a sinewave. I took 2 cycles to mean zoom to an extent on the graph that shows 2 full complete cycles of the sinewave.

Hope that helps!

The - pi/4 needs to be inside the sin argument as its a horizontal shift, not a vertical one.

Would that mean adding more brackets like this y = 8sin ((2pi*500000 x - π / 4))

You dont need both sets, but you do need the sin(2pi...-pi/4)