Derivatives using second diff

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MJ 2022-9-20

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1808715-derivatives-using-second-diff

编辑： MJ 2022-9-20

% This program computes for the Tangent Line / Normal Line of a curve % about a given point
                   %define x for symbolic processing
syms x y f(x) x0 y0 m
%IDENTIFY the function f(x)
f(x) = (4*x^2)-(2*x) + 1;
%DETERMINE the point of tangency (This will be a random point)
x0=randi([-5,5])
%SOLVE for the Ordinate of the point of tangency
y0=f(x0);  %Evaluate y given value fo x
y = (4*x0^2)-(2*x0) + 1;
%FIND the slope function
yprime(x) = diff(f(x));         %Solve for the first derivative
%Determine the slope at the given x0
m(x)= diff(y);          %Evaluate the slope
%Solve the equation of the tangent line
ytangent= m*(x-x0)+y0
%Solve the Equation of the normal line
ynormal= (-1.\m)*(x-x0)+y0
%DISPLAYING RESULTS
fprintf('The tangent line to f(x)=%s at (%.2f, %.2f) is y = %s \n',string(f(x)),x0,y0, string(ytangent))
fprintf('The normal line to f(x)=%s at (%.2f, %.2f) is y = %s \n',string(f(x)),x0,y0, string(ynormal))
%PLOTTING
g1=ezplot(f,[-15,15]);
set(g1,'color','b')
grid on
hold on
plot(x0,y0,'r*')
text(x0+1,y0,"Point of Tangency")
g2=ezplot(ytangent,[-15,15]);
text(5,5,["y(Tangent)=", string(ytangent)])
pause(1)
set(g2,'color','m')
pause(1)
g3=ezplot(ynormal,[-15,15]);
text(3,3,["y(Normal)=", string(ynormal)])
set(g3,'color','c');
title("Tangent Line and Normal Line")
Unable to perform assignment because the left and right sides have a different number of elements.
Variable ytangent has an incorrect value.
Variable ynormal has an incorrect value.
Please help me to correct my codes for ytangent and ynormal