求值cos[arctan2+arcsin(-1⼀3)]

rt
2024-12-29 02:21:34
推荐回答(1个)
回答1:

令A=arctan2,(0令B=arcsin(-1/3),(-π/2那么cos[arctan2+arcsin(-1/3)]=cos(A+B)
=cosAcosB-sinAsinB
=√5/5×2√2/3+2√5/5×1/3
=2√10/15+2√5/15
=(2√10+2√5)/15