I am trying to plot the parametric equation (t, -4, t^2 + 17), but am running into difficulties. I have been trying
fplot3(t, -4, t.^2+17)
But am getting the following error: Undefined function 'fplot3' for input arguments of type 'double'.
Any help is greatly appreciated!
fplot3 expects anonymous functions as inputs. So, you can use
fplot3(@(t) t, @(t) -4, @(t) t.^2+17)
Note the use of .^, which is element-wise power.
The above works, but gives a warning
Warning: Function fails on array inputs. Use element-wise operators to increase speed.
The reason is that the second function outputs a scalar, instead of an array the same size as the input t. To solve this, replace that function as follows:
fplot3(@(t) t, @(t) repmat(-4, size(t)), @(t) t.^2+17)
Also, you can specify the range of t as a fourth input:
fplot3(@(t) t, @(t) repmat(-4, size(t)), @(t) t.^2+17, [-10 10])
