九下82页第4题,用计算器求图中角A的正弦值、余弦值和正切值

1、sinA=1.7/√(1.7²+2.4²)≈0.5780
cosA=2.4/√(1.7²+2.4²)≈0.8160
tanA=1.7/2.4≈0.7083
2、sinA=1.5/√(1.5²+2²)=0.6
cosA=2/√(1.5²+2²)=0.8
tanA=1.5/2≈0.75
3、sinA=√(2.6²-2.2²)/2.6≈0.5329
cosA=2.2/2.6≈0.8462
tanA=√(2.6²-2.2²)/2.2≈0.6298