I've never used spreadsheets before, but I'm in a position where I have to. I got a calculus assignment, and it goes soemthing like this: I'm given a set of x and y values, and I need to choose a function (out of 25 given ones) which will serve as a curve of best fit. Seeing as I don't want to do all this manually, my instructor suggested that I use a spreadsheet, and said that once I figure out how to use one, it shouldn't be too much work. So, I created a spreadsheet, put in my x and y values, and now I need the function (f(x)) values in the third column. I also need a graph that will depict both, the data set, and the function on one grid. I will keep changing the function in the third column until I get the right one. Here's what my excel window looks like now:
How would I enter a function like y=3x * (1.4)^x into excel? Keep in mind that x is the first column, and y is what I need in the third column. I also need a graph.
once you have the formula working (you may want to play with the ƒx helper), select C3 again, then click and drag the little black square in the lower right corner that you can see in A1 (in your picture posted)
Is there a way for me to avoid entering a different $A value for each square? (i.e. can I select all the x values and have the resuling y value pop up in the C column for its corresponding x value?)
Hmmm...I'm starting to feel dumb...can you explain what you mean by that? I have the formula in C1, for instance: =3 * $A3 * POWER(1.4, $A3), in C2: =3 * $A4 * POWER(1.4, $A4), etc...what do you mean "drag the forumula"?
okay... see the small black square in the lower right corner of a selected cell? If you mouse over that, your cursor changes to a solid black plus/cross symbol, if you click and drag, the formula/pattern of data inside the selection will be expanded.. depending on what you have selected, Excel may do something you aren't thinking, but it's the best it can come up with given the selection.. Anyways, the $A locks the formula to the A column. Since the numbers aren't prefixed with dollars, they can freely change. If you drag to the right or left, the equation shouldn't change. But, if you drag up or down, the equation should increment the row (number) for each cell you expand the equation to...
alternativly you can highlight the cell and copy it and then highlight all the cells where you want it and paste it and it will be pasted to each one with the proper line number (this might make more sense to someone who's used to copying and pasting)