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

%W=3t^2+6t
%W=3t(t+2)
%(-(b)+sqrt(b^2-(4*a*c))/2*a)
%(-(b)-sqrt(b^2-(4*a*c))/2*a)
syms x positive
W=3*x.^2+6*x;
t1=solve(W == 3)

t1 = 

t2=solve(W == 9)

t2 = 

1

t3=solve(W == 45)

t3 = 

3

[Dyuman Joshi]

What exactly is your question?

[Walter Roberson]

That error does not show up in the code you posted.

[Jarrod]

No but the grader it needs to be submitted to gives this error everything is right i just need some leway to convert it

[Dyuman Joshi]

Although Watler has given you a working solution, I suggest you take the free Introductory course - MATLAB Onramp tutorial to learn the essentials of MATLAB.

Answer 1

[Walter Roberson]

x = double(t1);