Taylor's theorem - Wikipedia, the free encyclopedia
Essentially a Taylor Polynomial is a polynomial function used to approximate / evaluate a transcendental function.
If you think about it, how do you think a calculator finds the sine of an angle? Or the logarithm of a number? All that a calculator can do is add (and by extension, subtract, multiply, divide and exponentiate).
So it makes sense that when these transcendental functions need evaluating, there must be some combination of addition, subtraction, multiplication, division and exponentiation that can be done.