Question

How can I plot this function in MATLAB??

trap( -5, 5, 50)

function area = trap(x0, xn, N)

f=@(x) (6.*(exp(-x)).*(cos(x)).^2);

h = ((xn-x0)/N);

area=0;

while (x0

  

area = area+(h/2)*(f(x0)+f(x0+h));

x0= x0+h;

  

end

fprintf('area of trap', area);

end

Answer 1

Code:

function area = trap(x0, xn, N)
xSpan = linspace(x0, xn, N);
f=@(x) (6.*(exp(-x)).*(cos(x)).^2);

h = ((xn-x0)/N);

area=0;

while (x0 < xn)  
area = area+(h/2)*(f(x0)+f(x0+h));
x0= x0+h;
end

fprintf('area of trap', area);
plot(xSpan, f(xSpan))
title("area of f(x) = "+num2str(area))
end

Output:

run area = trap( -5, 5, 50) in command line and press enter

area of f(x) 275.4574 180 160 140 120 100 80 60 20 0 4 -2 4 -5 -3 -1 0 1 2 LO st 40