MATLAB help with functions

>> x=[0:1:10]

x =

0 1 2 3 4 5 6 7 8 9 10

>> y=(exp(1).^(0.2*x/0.2))*cos((100-1).^(1/x))

Error using /

Matrix dimensions must agree.

>> y=(exp(1).^(0.2*x/0.2))*(cos((100-1).^(1/x))

y=(exp(1).^(0.2*x/0.2))*(cos((100-1).^(1/x))

↑

Error: Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for

mismatched delimiters.

Did you mean:

>> y=[exp(1).^(0.2*x/0.2)]*[cos((100-1).^(1/x))]

Error using /

Matrix dimensions must agree.

>>

Im trying to insert this function to plot a graph

i already have the values of k,m and c

Answer 1

[John D'Errico]

Ok, you know that you have to use .^ to raise to a power. Then look carefully at the error message. What does it tell you?

"Error using  / 
Matrix dimensions must agree."

MATLAB did not like the / operator there? Why not? Because you did not use ./ instead.

You use the dotted operators to tell MATLAB to operate element-wise on a vector or array.

Where do we see a / in there?

y=(exp(1).^(0.2*x/0.2))*(cos((100-1).^(1/x))

I see two spots.

x/0.2

and

1/x

The fitrst case is not a problem, because MATLAB is able to divide a matrix or vector by a constant scalar with no problem. It is the second case where you have an issue. You need to use 1./x instead.

Oh, by the way, this is a silly thing to do here:

exp(1).^(0.2*x/0.2)

You clearly know what exp does!!!! So you might write

exp(0.2*x/0.2)

But even there, then why not make things even simpler? The last time I checked, we learned that:

0.2*x/0.2 == x

So you could just write your expression as:

y = exp(x)*(cos((100-1).^(1./x));

[rayan sharqawi]

https://uk.mathworks.com/matlabcentral/answers/487023-matlab-help-with-functions#answer_397901

Answer 2

[rayan sharqawi]

I still got this error