Is the number sentence true or false?

 cos(α+β)-cos(α−β)= 2cos α cosβ

Is the number sentence true or false?

 tan(π−θ)==−tanθ

Is the number sentence true or false?

 cos(α+β)- cos(α−β)= 2sin α sin β

Is the number sentence true or false?

 sin(α+β) + sin(α−β)=sin α cosβ

Is the number sentence true or false?

 cos(α+β) + cos(α−β)= 2cos α cosβ

Is the number sentence true or false?

 tan(α+β)- tan(α−β)=2cos α sinβ

Is the number sentence true or false?

 sin(α+β)- sin(α−β)=2cos α sinβ

Is the number sentence true or false?

 sin(π−θ)=−sinθ

 Is the number sentence true or false?

sin(α−β)/(cos α cos β) =tan α - tan β

Is the number sentence true or false?

cos(π−θ)=−cosθ