Highlight specific area of graph.

I have the following code:

syms x y
y = -x;
fplot(x, y, 'k')
hold on
y = x.^2-4;
fplot(x, y, 'k')
hold off 
xlim([-5 5])
ylim([-5 5])
box on
grid on
axis=gca;
axis.XAxisLocation = 'origin';
axis.YAxisLocation = 'origin';
title('Graph of y = xe^x')
xlabel('x')
ylabel('y')

which generates the following graph. Is there a way of colouring or highlighting the shaded area? Thank you.

Answer 1

[Star Strider]

You have to change the code slightly to do this:

x = linspace(-5, 5, 1000);
y1 = -x;
y2 = x.^2-4;
lidx = y1 >= y2;

figure
plot(x, y1, 'k')
hold on
plot(x, y2, 'k')
patch([x(lidx) fliplr(x(lidx))], [y1(lidx), fliplr(y2(lidx))], 'g', 'FaceAlpha', 0.5)   % <— ADD THIS LINE
hold off 
xlim([-5 5])
ylim([-5 5])
box on
grid on
axis=gca;
axis.XAxisLocation = 'origin';
axis.YAxisLocation = 'origin';
title('Graph of y = xe^x')
xlabel('x')
ylabel('y')

Experiment to get the result you want.

EDIT — (5 Mar 2019 at 00:39)

Added plot image: