Please help me with code for matlab, this is what I have so far

1. The principal stresses can be determined from the roots of the polynomial where and , .y, , are the applied normal stresses and Txy,Tyz,Tzw are the applied shear stresses. If the roots of the equation are 1, 2 and 3 (the three principal stresses), where 1 > 2 > 3, then the principal shear stresses are where mlax = 13. Determine the principal stresses and corresponding principal shear stresses when yz Zx Answer: = 160.7444, 2-54.8980,G=-95.6424, 12 52.9232,"23-752702, and 13-128.1934.] First, create the function as an M-file with input variables , , ,, Then, for the specified values of .0y, etc. plot the function using the lot or ezplo, over a sufficiently wide range of . Then, select from the graph, pairs of values of . Then, select from the graph, pairs of values of which have a zero crossing between them. Use these with the fzero command to find the principal stresses. Note that each call to fzero finds the root which lies between the pair of input numbers