#legend#graphlegend
x=linspace(0,2*pi,100);y1=1-x.^2/factorial(2);y2=y1+x.^4/factorial(4);y3=cos(x);plot(x,y1,'k:')legend('2 terms approx')hold onplot(x,y2,'k--')legend('3 terms approx')hold onplot(x,y3,'r')legend('cos(x)')xlabel('x')ylabel('y')n=-180:180;x=(pi/180).*n;y=sin(x);y2=sin(x).*cos(x);y3=cos(x);% Plot on left axis
yyaxis lefth1 = plot(n,y, '-k', 'LineWidth', 1, 'DisplayName', 'h1'); set(gca, 'YColor', 'k') % set y axis color to same as line color
hold onh3=line(n,y3,'Color','r','LineWidth',2, 'DisplayName', 'h3');% Plot on right axis
yyaxis righth2 = plot(n,y2, '-b', 'LineWidth', 1.5, 'DisplayName', 'h2'); set(gca, 'YColor', 'b') % set y axis color to same as line color
n=-180:180;x=(pi/180).*n;y=sin(x);y2=sin(x).*cos(x);y3=cos(x);% Plot on left axisyyaxis lefth1 = plot(n,y, '-k', 'LineWidth', 1, 'DisplayName', 'h1'); set(gca, 'YColor', 'k') % set y axis color to same as line colorhold onh3=line(n,y3,'Color','r','LineWidth',2, 'DisplayName', 'h3');% Plot on right axisyyaxis righth2 = plot(n,y2, '-b', 'LineWidth', 1.5, 'DisplayName', 'h2'); set(gca, 'YColor', 'b') % set y axis color to same as line color% Produce left-axis legend
legend([h1,h3], 'Location', 'NorthWest')% Create invisible axis in the same position as the current axes
ax = gca(); % Handle to the main axes
axisCopy = axes('Position', ax.Position, 'Visible', 'off');% Copy objects to second axes
hCopy = copyobj(h2, axisCopy); % Replace all x values with NaN so the line doesn't appear
hCopy.XData = nan(size(hCopy.XData)); % Create right axis legend
legend(hCopy, 'Location', 'NorthEast')
function [approx] =cos1(x,n)%Calculates the Malcurin series approximation to cos(x)
approx=0;for i=0:n-1 approx=approx+(1)^i*x^(2*i)/factorial(2*i);end ^ you forgot this!
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