Problem using primary and subfunction

I am having a problem with using the subfunction to find the zeros of an equation.

Here is the problem:

Use a primary function with a subfunction to compute the zeros of the function 3x^3 - 12x^2 - 33x + 80 over the range -10<x<10

Please Help! Thank you.

[Jan]

Do you have a question?

See: http://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers