Using fzero to find variation

Use fzero to determine by how much the value of D can vary from it’s optimal value before the tension increases by more than 10% from it’s minimum, and display this value in the Command Window.(this is what I need to accomplish)

I have already written the rest of the program that gives me the optimal value D and the value of the tension while using a anonymous function. Not sure how to exactly go about using fzero in order to find the max variation of D.

Answer 1

[Walter Roberson]

If you know the optimal D and optimal tension, and you have a function that calculates tension given D, then if you find the zeros of

calculate_tension(optimal_D-deltaminus)-.9*tension
calculate_tension(optimal_D+deltaplus) - 1.1*tension

then deltaminus and deltaplus are the values being asked for.