loop function help please

Use for loops to give the values of the following function: f(x) =     3x2 + 5x – 7                  x < 0            3x + 4                       x >= 0 

for -10 <= x <= 10 in steps of 1

Answer 1

[David Hill]

x=-10:10;
for k=1:length(x)
    if x(k)<0
        f(k)=3*x^2+5*x-7;
    else
        f(k)=3*x+4;
    end
end