Question

已知5sin(α+β)+3sinα=0,求tan(α+)·cot的值.

Answer 1

解:由已知5sin(α+β)+3sinα=0得

5sin［(α+)+］+3sin［(α+)-］=0,

5sin(α+)cos+5cos(α+)sin+3sin(α+)cos-3cos(α+)sin=0,

∴8sin(α+)cos+2cos(α+)sin=0.

∴tan(α+)cot=-.