Question

expansion of (z²+1/z)²

Answer 1

Answer:

This is in the form (a+b)²

(a+b)² = a²+b²+2ab

In this case,let z² be a, and 1/z be b

So, (z²+1/z)² = (z²)² + 1/z² + 2(z²)(1/z)

= z⁴ + 1/z² + 2z