預科Applied Maths...
btw, Taylor series 是用來估計當x在a附近時f(x)的近似值
( f(x) - f(a) ) / (x - a) = f'(a) 應該是( f(x) - f(a) ) / (x - a) = f'(ξ), where ξ between x and a 才對吧...這是mean value theorem
好像prove個error term時會用到此theorem...但我不清楚,畢竟不在課程範圍內(逃)
另外,個series是「強行」let出來的,即是let f(x)= A+B(x-a)+C(x-a)^2+..., where A,B,C,... are constants
再不斷put a, differenciate f(x)得出各常數