Question

sin2α=五分之三, tan(α-β)等于二分之一,则tan(α+β)=?

Answer 1

∵Sin2a等于五分之三
∴cos2a=-4/5
tan2a=-3/4
∴tan(a+b)=tan(2a-(a-b))
=[tan2a-tan(a-b)]/[1+tan2atan(a-b)]
=[-3/4-1/2]/[1+(-3/4)*1/2]
=-(5/4)/(5/8)
=-2