MATLAB Answers

0

Hi, so I'm trying to plot this equation: y=-(sqrt(288-2*x.^4))/x with x=0:0.05:3.267 but y is giving me a single answer (-6.55) and when i do plot(x,y) the graph is empty! Can someone help me please!

Asked by Seamus Pugh on 29 Feb 2016
Latest activity Answered by Jos (10584)
on 29 Feb 2016
Hi, so I'm trying to plot this equation: y=-(sqrt(288-2*x.^4))/x with x=0:0.05:3.267 but y is giving me a single answer (-6.55) and when i do plot(x,y) the graph is empty! Can someone help me please!

  0 Comments

Sign in to comment.

Tags

No tags entered yet.

3 Answers

Answer by Ingrid
on 29 Feb 2016

you have forgotten to also use the ./ operator instead of the / operator. The code below should give what you try to achieve
x=0:0.05:3.267;
y=-(sqrt(288-2*x.^4))./x;
plot(x,y)

  0 Comments

Sign in to comment.


Answer by Torsten
on 29 Feb 2016

You forgot a dot (.) in front of "/x".
Best wishes
Torsten.

  0 Comments

Sign in to comment.


Answer by Jos (10584)
on 29 Feb 2016

The plot is not empty. It contains 66 points all having the same y value (at y=-6.5514), which can be seen here:
plot(x,y,'bo')
Why is y a scalar? Because, as others told you already, there is a difference between element-wise (.* and ./) and matrix operators (* and /):
x = 1:4
x ./ x
x / x

  0 Comments

Sign in to comment.