How to plot a single variable function with constraints

Hello, I am trying to plot f(x) = 4 - x*sin(x) with constraints x>=6, x<=9 and log(x)>= -1. I tried using meshgrid but the graph came out wrong + it was in the 3rd dimension. Can anyone tell me how I should go about plotting a simple function with these constraints? Thank you!

[Ameer Hamza]

What does the constraint log(x)>= -1 mean? Does it mean x >= exp(-1)? How does this combine with x>=6, x<=9?

[Mihai Giurca]

I'm honestly not sure, my professor gave me these constraints and I'm not sure what the log is supposed to mean.

[Huy Phan Dang]

log(x) or lg(x) can mean log 10 of x, my education system alway use lg(x) for log 10 of x as shortcut so it might be what your professor meant

Answer 1

[Ameer Hamza]

f = @(x) 4 - x*sin(x);
fplot(f, [6 9]);

Answer 2

[Matt J]

You can assign NaN to anything you don't want plotted. Example,

x=linspace(0,2,1000);
f=sin(x);

f( 0.5<=x & x<=1)=nan;

plot(x,f);