Question

Evaluate ✓dz/z-7z+12 where c is the circle [z]=3.5

Answer 1

c=4.5 cm

hope it helps you

Answer 2

Answer:

Cauchy's Integral theorem ∫Cf(z)z−zodz=2πif(zo) .Clearly the singularity z=7+4√12 lies outside the contour and the singularity 7−4√12 lies inside it so f(z)=(z3+z+1)z−7+4√12 .Using Cauchy's Residue theorem we get the contour integral as 2πif(7−4–√12)