223

a)
$\left(0.6{,}\ 0.8\right)$
$\sin53°=0{,}7986...\approx0{,}8$
$\cos53°=0{,}6018...\approx0{,}6$
b)
$\left(-0.8{,}\ 0.6\right)$
$\sin143°=0{,}6018...\approx0{,}6$
$\cos143°=-0{,}7986\approx-0{,}8$