Question

Small computers often use table to estimate the cosine curve, but if high precision is needed, a series solution can be used instead. A Taylor series solution for cosine is presented below

cosx=1-x^2/2!+x^4/4!-x^6/6!+x^8/8!…

1. Create a Matlab function that can calculate an estimate for cos(x) given X and the number of terms. Test it for cos(2) with 10 terms in the series and cos(7) with 200 terms.

Answer 1

function result = myCos(x, n)
    result = 0;
    sign = 1;
    for i=0:n-1
        if factorial(2*i) ~= Inf
            result = result + (sign*(x^(2*i))/factorial(2*i));
            sign = -1*sign;
        end
    end
end

myCos(2, 10)
myCos(7, 200)