tan(a+β)= 2 tan(a-β)= -3/5 则tan2β=?(请给出解析)
问题描述:
tan(a+β)= 2 tan(a-β)= -3/5 则tan2β=?(请给出解析)
答
tan2β
=tan[(a+β-(a-β)]
=[tan(a+β)- tan(a-β)]/[1+tan(a+β)*tan(a-β)]
=(2+3/5)/(1-6/5)
=-13