It is likely easiest to evaluate the function, then interpolate to find the intersection.
Example —
x = linspace(0, 2);
vector = x.^2;
f = @(z) 5./(1 + z);
intx = interp1(f(x) - vector, x, 0, 'linear');
figure
plot(x, vector)
hold on
plot(x, f(x))
plot(intx, f(intx), 'pg', 'MarkerSize',10)
hold off
grid
legend('Vector', 'Evaluated Function', 'Intersection')
.
