Calculus is a very large topic, are there any particular areas you need help with? The All About Circuits reference section has some good information for calculus, found here. Let us know if there are specific problems. Edit: I am also moving this into the Math section.
i think there is general secret with calculus that leads up to differential equations. First of all, trying to interpret and solve mathematics with symbolism and formulas isn't the best approach. working through lots of detailed examples a healthy way to figure things out. I'm saying stuff everyone knows but it is good to mention Derivative, a better word is (rate of change of a variable)/ (rate of change of another variable) say you take a derivative of a specific area you are basically finding the slope so say you take a derivative with variables of position, like x in meters, then you are finding out the velocity, meters per whatever unit you taking it respect to. Example with x as distance in units of meters in relation to y in units of seconds: y = x^3, the derivative is y'= 3*x^2. so say at x=5, the distance is 125 meters, and the velocity, or for the derivative, is 75 meters per second, or x's per unit of y Take the derivate of the velocity and you have the accelerations. the rate of change of velocity. Which is the same as taking the derivative of the distance twice. derivative and antiderivates can be used to find max and mins of all types of parameters. im tired of typing, maybe you should say what parts are the confusing. and then solving sets of equations, if you can master matrices you can rule math. as for calculs with different coordinate systems have the whole thing of equations available all on a sheet for reference on converting. and have all the trignometric identities on a paper always available for reference along with imaginary numbers, like e^-j*pi stuff. and master the calculator, the amount of crap it can do is amazing if you buy the right one.
I think you mean x is the unit of time (i.e. seconds) and y is the unit of distance (i.e. metres). Good post, Tada.