Question

Use MATLAB to find the best a, b, and c coefficients for curve y=a*(sqrt(x)/x)+bx+c to fit

these data points: (x,y)=[(0.1 2.5) (1.2 1.64) (2.1 1.67) (3.35 1.81) (4.5 1.9)]
Use fprintf to show the a,b,c values you obtained, also plot the points and fitted curve in one plot (use proper labels.)

Answer 1

the matlab script is as follows:

x=[0.1 1.2 2.1 3.35 4.5];

y=[2.5 1.64 1.67 1.81 1.9];

% defining parameters in 1 variable

%c(1)=a;

%c(2)=b;

%c(3)=c;

% defining the non linear curve

F=@(c,xdata) c(1)*(sqrt(xdata)/xdata)+c(2)*xdata+c(3);

% setting up initial value

c0=[0 1 1];

% solver for curve fitting

[c,resnorm,~,exitflag,output] = lsqcurvefit(F,c0,x,y)

fprintf(' the values of coeeficients a,b,c are %d, %d, %d',c(1),c(2),c(3));

plot(x,y,'ro')

title('Data points')

hold on

for i=1:5

y1(i)=F(c,x(i));

end plot(x,y1)

hold off