Question

tana-1/cosa=√3求cosa/(sina+1)

写出过程

Answer 1

tana-(1/cosa)
=(sina/cosa)-(1/cosa)
=(sina-1)/cosa=根号3.
而:
[(sina-1)/cosa]*[(sina+1)/cosa]
=[(sina)^2-1]/[(cosa)^2]
=-1.
所以:
(sina+1)/cosa
=-1/根号3
所以:
cosa/(sina+1)
=-根号3.

Answer 2

tana-1/cosa=√3
sina-1==√3cosa
sina-√3cosa=1
2sin(a-π/3)=1
sin(a-π/3)=1/2
a=2kπ+π/2 或a=2kπ+7π/6
由题得cosa 不等于0 所以a=2kπ+7π/6
所以cosa/(sina+1)
=-根号3/3.

Answer 3

tana-1/cosa=√3
sina-1==√3cosa
sina-√3cosa=1
2sin(a-π/3)=1
sin(a-π/3)=1/2
a=2kπ+π/2 此时 cosa=0 应舍去。
或a=2kπ+7π/6
cosa=-√3/2 sina=-1/2

故cosa/(sina+1)=-√3

Answer 4

解一：简便算法。因为1/2和根号3/2平方和为一，又有a∈(0,п)，所以sina=1/2，cosa=-根号3/2 tana=-根号3/3 解二：由(sina+cosa)^2=1+2sinacosa 得sinacosa=-根号3/4 tana+cota=(sina^2+cosa^2)/(sinacosa) =1/(sinacosa)=-4/根号3 即tana+1/tan...