Jan 14, 2002 ------------ - Intro to 3414 - what a wonderful course this is! :) - applications in - Google - Microsoft Word (drawing) - Speedometers and Odometers - In short, they are everywhere! - Basic approach - "how to do mathematics by computer" - why is this a big deal? - "computers are stupid" - Classic example - a = 4./3.; b = a - 1.; c = b + b + b; print (c - 1); - Review of Taylor's series - 1+2+..+k is unbounded - so is 1+1/2+1/3+..+1/k ! (even though each number is smaller than the previous) - How do you slightly modify the second to get a bounded series? - use alternating signs - 1-1/2+1/3-1/4... => ln 2 - use factorials - 1/1!+1/2!+1/3!+... => e-1 - use squared entries - 1+1/4+1/9+1/16+.. => ??? - First two are well known examples of Taylor's series expansions - first works when |x| < inf - second works in -1 < x <= 1 - Review Taylor's series expansion - When does the series represent the function? - Taylor's theorem tells us this - Examples - f(x) = 2x^2 + 3x + 1 - f(x) = sin x - In general, Taylor's series is good for approximating f() near the point of expansion (i.e., c) - What happens if we move away from c? - Alternating Series Theorem - Worked out example 8 from your textbook