Trying to calculate partial sums of e^10 in Matlab?

Question

I\'ve written the function:

function [sum] = func(a,b)
sum = 0;
for i = 0:b
    sum = sum + ((a.^i)/(factorial(i)));
end

In the console, the co

Answer 1

f = @(x,i) (x.^i)./factorial(i)
r=f(10,0:50); %50 terms in taylor series more than enough for good approx.
cumsum(r)

1.0e+04 *

0.0001
0.0011
0.0061
0.0228
....
2.202646579479054
2.202646579480280

Verify

>> exp(10)
    2.202646579480672e+04

Answer 2

Well, if you don't index sum with i, you return a single value.

Try instead:

function [sum] = func(a,b)

% Pre-allocate sum at the right size
sum = NaN(1,b+1);

% Compute
for i = 0:b
    sum(i+1) = sum(i+1) + ((a.^i)/(factorial(i)));
end

Best,