## College Algebra 7th Edition

$\overline{z^2}=\overline{(a+bi)^2}=\overline{a^2-b^2+2(ab)i}=a^2-b^2-2(ab)i$ $\overline{z}^2=\overline{(a+bi)}^2=(a-bi)^2=a^2-b^2+-2abi$ Thus they are equal thus we showed what we had to.