Variable q10 must be of data type double. It is currently of type sym. Check where the variable is assigned a value.

I was wondering what to do to chane my data type to double? I am very new to matlab and this is the only error that is coming up in my assignment

P = [3,2,-1];
Q = [5,0,1];
n = [4,7,-2];
syms x y z
f(x,y,z) = (4*(x-3)+7*(y-2)-2*(z+1));
q10 = abs((f(5,0,1))/(norm(n)))

q10 = 

[Walter Roberson]

double(q10)

Answer 1

[Steven Lord]

As you can see from the fact that your code ran in MATLAB Answers, your code does work. I'm assuming that you're running this in something like MATLAB Grader or MATLAB Onramp that checks certain qualities (chosen by the problem author) about the results.

In that case you're likely going to want to convert the symbolic answer into its numeric (double) representation.

P = [3,2,-1];
Q = [5,0,1];
n = [4,7,-2];
syms x y z
f(x,y,z) = (4*(x-3)+7*(y-2)-2*(z+1));
q10 = abs((f(5,0,1))/(norm(n)))

q10 = 

D = double(q10)

D = 1.2039

format longg
D

D = 
          1.20385853085769