Giá trị của B=cos44550−cos9450+tan10350−cot(−15000) là bn? 30/09/2021 Bởi Brielle Giá trị của B=cos44550−cos9450+tan10350−cot(−15000) là bn?
$B= cos(135^o+24.180^o)-cos(90^o+52.180^o)+tan(135^o+5.180^o)+cot(60^o+8.180^o)$ $= cos135^o-cos90^o+tan135^o+cot60^o$ $= -cos45^o-tan45^o+tan30^o$ $= \frac{-\sqrt2}{2}-1+\frac{\sqrt3}{3}$ $=\frac{2\sqrt3-3\sqrt2+6}{6}$ Bình luận
$B= cos(135^o+24.180^o)-cos(90^o+52.180^o)+tan(135^o+5.180^o)+cot(60^o+8.180^o)$
$= cos135^o-cos90^o+tan135^o+cot60^o$
$= -cos45^o-tan45^o+tan30^o$
$= \frac{-\sqrt2}{2}-1+\frac{\sqrt3}{3}$
$=\frac{2\sqrt3-3\sqrt2+6}{6}$