for maxima diff(i) w.r.t.time=0 so 3cosΔt-4sinΔt=0

which gives tanΔt=3/4 now we can put it back into the original equation to find the answer to my question which is what i did

where tan alpha = 3/4

This uses the compound angle formula http://www.mathsrevision.net/advanced-l … e-formulae

Bob

]]>http://en.wikipedia.org/wiki/Root_mean_square

which do you think applies?

]]>i= I cos (omega)t i know that I is the maximum value of current and find the RMS as I/root(2) which is not the case for this function.... i seem bit silly but i feel differentiating might help but i am not sure about it...]]>

Just a question. This delta function, is a Dirac delta function, an impulse function or just a straight difference operator?

]]>then the root mean square value of current is....

can anybody tell me a way to answer this using either calculus or a rough graph?]]>