Question

已知tan(α+p)=3,tan(a-p)=5,求tan2a,tan2p的值

Answer 1

(1) tan(α+p)+tan(a-p)]/[1-tan(α+p)tan(a-p)=tan(a+p+a-p)=tan2a

=>tan2a=[3+5]/[1-3*5]=-4/7

(2)tan(α+p)-tan(a-p)]/[1+tan(α+p)tan(a-p)=tan(a+p-a+p)=tan2p

=>tan2p=[3-5]/[1+3*5]=-1/8