(本题6分) (1)已知:sinα·cos60º=,求锐角α; (2)计算:.
-24+[(-4)2-(1-32)×2]
(本题16分)计算: ⑴ ⑵ (3) -14×(-2)+(-5)×2+4× (4)
已知,求的值,
计算:,
计算: (1)(2)