Pls solve this also (°-°)

1.	Pls solve this also (°-°)
Answer» align="absmiddle" alt="\large\rm{f(Z) = \frac{7-z}{1-z^{2}}}" class="latex-formula" id="TexFormula1" src="https://tex.z-dn.net/?f=%5Clarge%5Crm%7Bf%28z%29%20%3D%20%5Cfrac%7B7-z%7D%7B1-z%5E%7B2%7D%7D%7D" TITLE="\large\rm{f(z) = \frac{7-z}{1-z^{2}}}"> $\large\rm { = \frac{7-(1+2i)}{1-(1+2i)^{2}}}$ $\large\rm { = \frac{6-2i}{1-1+4-4i}}$ $\large\rm { = \frac{6-2i}{4-2i}}$ $\large\rm { = \frac{6-2i}{4-2i} \times \frac{4+4i}{4+4i}}$ $\large\rm { = 1 + \frac{1}{2} i}$ SINCE $\large\rm { z = 1 + 2i}$ $\large\rm { \therefore \|z\| = \sqrt{(1)^{2} +(2)^{2}}}$ $\large\rm { \|z\| = \sqrt{5}}$ .....(1) $\large\rm { \therefore f(z) = \sqrt{ (1)^{2} + \big ( \frac{1}{2} \big ) ^{2}}}$ $\large\rm { = \frac{\sqrt{5}}{2}}$ $\large\rm { = \frac{\|z\|}{2}}$ from (1) $\large\boxed{\bf { \therefore f(z) = \frac{\|z\|}{2}}}$

Answer»

align="absmiddle" alt="\large\rm{f(Z) = \frac{7-z}{1-z^{2}}}" class="latex-formula" id="TexFormula1" src="https://tex.z-dn.net/?f=%5Clarge%5Crm%7Bf%28z%29%20%3D%20%5Cfrac%7B7-z%7D%7B1-z%5E%7B2%7D%7D%7D" TITLE="\large\rm{f(z) = \frac{7-z}{1-z^{2}}}">

$\large\rm { = \frac{7-(1+2i)}{1-(1+2i)^{2}}}$