Question

已知a∈(0,π/2)，sina=3/5，求tan(a+π/4)

写出解答过程,谢谢,

Answer 1

因为a∈(0,π/2),sina=3/5,所以cosa=根号(1-sin²a)=4/5
tana=sina/cosa=3/4=0.75
tan(a+π/4)=(tana+tanπ/4)/(1-tana*tanπ/4)=(0.75+1)/(1-0.75*1)=7

Answer 2

a∈(0,π/2),sina=3/5,故cosa=根号(1-sin²a)=4/5

tana=sina/cosa=3/4=0.75

tan(a+π/4)=(tana+tanπ/4)/(1-tana*tanπ/4)=(0.75+1)/(1-0.75*1)=7