B Formulas for the alternating current and voltage

AI Thread Summary
The discussion centers on the correctness of formulas for current and voltage in sinusoidal functions. The user presents two sets of formulas: v=v0cos(wt) and i=i0cos(wt), questioning their validity compared to the commonly found v=v0sin(wt) and i=i0sin(wt). It is clarified that both sets represent the same sinusoidal function but differ in phase, with the cosine functions leading the sine functions by a phase of π/2. At t=0, the cosine functions yield v=v0 and i=i0, while the sine functions yield v=0 and i=0. Understanding the phase difference is essential for correctly applying these formulas in electrical contexts.
wolly
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Hi,I have found in my textbook the formulas for both current and voltage and I have no idea if they are right or wrong. Can someone help me with these formulas?
v=v0cos(wt)
i=i0cos(wt)
Is this correct? In google when I search for the answers I get something else:
v=v0sin(wt)
i=i0sin(wt)
 
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They are same sinusoidal function with only difference of phase.　
Fot t=0
The former v=v0 i=i0
The latter v=0 i=0
 
Yes if you know abit of trigonometry it is $$\cos(\omega t)=\sin(\omega t+\frac{\pi}{2})=\sin(\omega(t+t_0))$$ where ##t_0=\frac{\pi}{2\omega}## the phase difference in seconds.
 

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