What's the problem?

Question

编辑： James Tursa 2017-10-13

I do not know what the code problem is for not plotting:

x=-100:0.001:100;
y=3x+1./(x+2)*(x-3);
plot(x, y, 'k-', 'LineWidth', 2);
grid on;
xlabel('X', 'FontSize', 20);
ylabel('Y', 'FontSize', 20);

Answer 1

James Tursa 2017-10-13

编辑：James Tursa 2017-10-13

You can't use 3x in MATLAB ... you have to use 3*x. And you need to use the element-wise .* operator instead of the matrix multiply * operator.

y = 3*x+1./(x+2).*(x-3);

And, if you meant for all of the (x+2)*(x-3) stuff to be in the denominator, then you would need to use parentheses:

y = 3*x+1./((x+2).*(x-3));