The CP I have is -1.17528. How do I find the MCR and CP iteratively? Please help

c. From the plot, what is Mcr and Lp,cr of the airfoil? 5. Reduce the magnitude of the minimum Cp from the previous question by 25% (multiply by 0.75). Now use the iterative method to find Mer and Cp.er c. From the plot, what is Mcr and Lp,cr of the airfoil? 5. Reduce the magnitude of the minimum Cp from the previous question by 25% (multiply by 0.75). Now use the iterative method to find Mer and Cp.er