>>81476016okay I can teach you a bit then
>f(x)f stands for "function." A function is a process that turns one number into another. For example, you can have a function that doubles numbers, and that would turn the input 2 into the output 4. x is a variable. This means that it represents any given number. f(x) is saying "if I put any given number into this function, here is what will happen." If your function doubles numbers, then f(x) = 2x. This might be confusing at first, but over time you'll encounter it a lot and you'll get it.
>limA limit is the number that a function approaches as it approaches a given number. This is almost always used in reference to infinity. For example, with our doubling function, as the number you're inputting gets larger, so does the output number. Thus, you'd say that the limit as that function approaches infinity is infinity. If the function were "multiply the number by negative one," then the output would get smaller as the input got larger, and you'd say the limit as the function approached infinity was negative infinity.
>cos and sinThese are both from trig, like you said. They represent the ratios of different sides of a right triangle. I kind of forgot about this when I took calculus because it wasn't super important.
I'm sorry if this was confusing. I'm a teacher, but this sort of thing can be hard to describe over text.