How do calculators solve algebra, calculus, etc.

[MolotovCocktail]

How do calculators do this? From what I understand, a computer/calculator can only add or subtract, and nothing else. How exactly does it graph polynomials, calculate pi to hundreds of digits, etc.

 

I know how it does some of the things: e.g. it sums a series when calculating the cos(1), but what does it do when its calculating anything complicated like logarithms?

[Pre4edgc]

Well, graphing calculators have functions built into them that you just fill in. Also, it has a y= section (I have that kind: TI-82) that you plug, well, y= equations. I haven't figured out how to graph binomials or higher, but you can solve them as well in the matrix function. It's pretty cool. And I'm not sure about logarithms...

[CPL.Luke]

alot of time figuring out how to do various mathematical operations in a computer. there are now hardware functions for addition and division, and there are algorithms for graphing.

 

the graphing algorithm works the same way that a human works as they graph, plot a number of points, and then a draw lines to connect the points. By plotting enough points te straight lines begin to look curved.

[ecoli]

from what I understand, it's all done with algorithims of approximations and summations.