maclaurin series code problem

I keep getting "index exceeds matrix dimensions" but i don't see a problem. Can anyone see why this isn't working?

n = 4;

es = 0.5*10^(2-n);

x = 5;

approx(1) = 5;

analytical = sin(5)

et(1) = (analytical-approx(1))/analytical*100

ea(1) = NaN

for k = 1:20

    approx(k+1) = approx(k)+(-1)^(k)*x^(2*k+1)/factorial(2*k+1)

    ea = (approx(k+1)-approx(k))/approx(k+1)*100

    et = (analytical-approx(k+1))/analytical*100

    if abs(ea(k+1))<es

        break
    end
end

I greatly appreciate the help.

Answer 1

[Iain]

 abs(ea(k+1))<es

in your code, ea is a scalar, and you're trying to access the k+1th element, which is the error.

[Mary Jeppson]

Oh, right. Thank you very much.