doc sqrt
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f=@(x) sin(x) x=-pi:pi/256:pi;y=f(x);plot(x,y) xlabel(\'x\'),ylabel(\'y\'),title(\'test\') axis([-pi pi -2.8 2.8]) set(gca,\'xtick\',pi*(-3:1/2:3))
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linspace(2,8,4) 公差数列
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