What happens in Prob. 7 if we replace sin z by cos z = sin (z + 1/2π)?

Data from Prob. 7

Let D: 0 ≤ x ≤ 1/2 π, 0 ≤ y ≤ 1; D* the image of D w = sin z; and Φ* = u² - v². under and What is the corresponding potential Φ in D? What are its boundary values? Sketch D and D*.