Question 15****+For which positive real \(r\) do the roots of \(z^3=re^{i\pi/3}\) have modulus \(2\)?
Question 16****+For which integers \(k\) should be used to list the distinct roots of \(z^6=5e^{i\pi/7}\), and why?
Question 18*****A learner solves \(z^3=1+i\) using only \(\arg(1+i)=\pi/4\) and gives one root. Explain the missing step.
Question 20*****Show that if \(w\) is one solution of \(z^n=a\), then every solution is \(w\omega\), where \(\omega^n=1\).