Prove that (a) │ z1 │-│ z2 │ ≤ │z1 - z2│ ≤ │ z1 │+ │ z2 │ (b) │ z1 │-│ z2 │ ≤ │z1 + z2│ ≤ │ z1 │+│ z2 │ where z1 , z2 are complex numbers.

Functions of a Complex Variables Prove that: (a) │ z1 │-│ z2 │ ≤ │z1 - z2│ ≤ │ z1 │+ │ z2 │ (b) │ z1 │-│ z2 │ ≤ │z1 + z2│ ≤ │ z1 │+│ z2 │ where z1 , z2 are complex numbers.

Partial Induction Proof of Cauchy's Integral Formula

see attached file...it is a full induction proof of Cauchy Integral Formula, with the base case step missing. All I have to do is show that it holds for "n=1", using the rest of the proof as an example...however i am having trouble showing it.

If u = sin x . cosh y + 2cos x . sinh y + x2 – y2 + 4xy , then prove that u is a harmonic function and find the analytic function f(z) = u + iv .

Functions of a Complex Variables Analytic Functions If u = sin x . cosh y + 2cos x . sinh y + x2 – y2 + 4xy , then prove that u is a harmonic function and find the analytic function f(z) = u + iv . See attached file for full problem description.

Complex Variables

If a > e prove that the equation a*z^n=e^z has n solutions (counting multiplicities) inside of the circle |z|=1.

Analyticity proof

Suppose that f: C->C and that f is analytic at a point z0 element of C. Prove that there exists a real number r>0 such that, the nth derivative of z0=[n!/(2 pi r^n)]x[int(e^(-niy)f(z0+re^(iy)) from 0 to 2pi with respect to y for all n element of Natural numbers.