$50000\left(1 + \frac{0.08}{4}\right)^{8} \approx \$58,582.67$

$50000(1 + 0.08)^2 \approx \$58,320$

$50000(1.08)(1.02)^4 \approx \$59,500$

$50000 + 50000(0.08)(2) = \$58,000$