How would I plot the function p(x)=e^(-0.5x)*(4-x)-2 in the range of -2 to 10 as well as its derivative?

How would I plot the function p(x)=e^(-0.5x)*(4-x)-2 in the range of -2 to 10 as well as its derivative? When I run it I get an invalid operator so I assumed I had to use . after the variables but that gives me the error: Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters. Can someone please help me out.

x = -2:0.1:10;
p = (exp(-0.5*x.)*(4-x.))-2;

Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.

pp = 0.5*exp(-0.5*x.)*x.-3*exp(-0.5*x.);

plot(x,p)

Answer 1

[Les Beckham]

You had the '.' characters in the wrong place; they go right before the '*' to get element-by-element multiplies.

x = -2:0.1:10;
p = (exp(-0.5*x) .* (4-x)) - 2;
pp = 0.5*exp(-0.5*x) .* x - 3*exp(-0.5*x);

plot(x, p, x, pp)
grid on