Answer
$\approx 2.853+0.927i$
Work Step by Step
Evaluate the trigonometric expressions using a calculator, then simplify to obtain:
$3\cdot (\cos (\frac{\pi}{10})+i\cdot \sin(\frac{\pi}{10}))
\\=3(0.9510565163+i\cdot0.3090169944)
\\\approx2.853+0.927i$