Two functions equal for which values?

Hi,

If i have 2 functions, in this case:

alfa=linspace(0,25);

cl_1=@(alfa)a0*alfa-a0*deltaalfa*((a0*alfa/(clmax+a0*deltaalfa))).^n1;

cl_2=@(alfa)clmax-deltacl+(1/5)*(a0*alfa-clmax);

CL_1=cl_1(alfa);

CL_2=cl_2(alfa);

If i now want to put those equal to eachother and find for what alfa values those are equal, how do i do that?

Best regards,

Daniel

Answer 1

[Star Strider]

Without your constants, I cannot write more exact code. There are a few ways to estimate the approximate values of ‘alfa0’ that are close to the intersections, so you would calculate them and loop through them to get each result from fzero.

The general idea to get the real values of the intersections of the two curves:

cl_1=@(alfa)a0*alfa-a0*deltaalfa*((a0*alfa/(clmax+a0*deltaalfa))).^n1;
cl_2=@(alfa)clmax-deltacl+(1/5)*(a0*alfa-clmax);

alfa0 = ...;                                                            % Initial ‘alfa’ Estimate
intersec = fzero(@(alfa) cl_1(alfa)-cl_2(alfa), alfa0)                 % Estimate ‘alfa’ At One Intersection

There are other functions, such as fsolve, as well. Note that without knowing what ‘n1’ and the other constants are, there is no way to know if there are any intersections.