plot of y = 2.*(x.^4 - x.^2) isn't right

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Anna 2022-3-27

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评论： Anna 2022-3-27

I set x = linspace(-10, 10); y = 2.*(x.^4 - x.^2); plot(x, y)

and the graph is not correct. what did I do wrong?

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Mahmoud Ashraf 2022-3-27

hi can you write you equation (handwritten)

DGM 2022-3-27

在 MATLAB Online 中打开

Seems fine to me.

x = linspace(-10, 10);

y = 2.*(x.^4 - x.^2);

plot(x, y)

It might be that you're working in a figure that's already had hold on set, and the axis extents are such that the curve is not visible. If that's the case, either clear the figure (clf) or set the axis limits to something appropriate (use xlim() or ylim())

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Dave B 2022-3-27

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在 MATLAB Online 中打开

I'm pretty sure that's correct, were you expecting to see more of a w-like shape? You might have to zoom in a bit for that (and it helps to add some more points:

tiledlayout(1,2)

nexttile

x = linspace(-10, 10);

y = 2*(x.^4 - x.^2);

plot(x, y)

title('default limits')

nexttile

x = linspace(-10, 10, 1000);

y = 2*(x.^4 - x.^2);

plot(x, y)

ylim([-1 6])

title('more points, zoomed in')