請問條數點計

1. sin θ = sqrt(1 - cos^2 θ) = sqrt(1 - (4/5)^2) = 3/5
cos θ = 4/5
=> 1 + tan θ
= 1 + sin θ / cos θ
= 1 + (3/5) / (4/5)
= 1 + 3/4
= 7/4

2. 1/tanθ + sin θ / (1 + cosθ)
= cosθ / sinθ + sin θ / (1 + cosθ)
= [cosθ (1+ cosθ) + sin^2 θ] / [sinθ (1 + cosθ)]
= (cosθ + cos^2 θ + sin^2 θ) / [sinθ (1 + cosθ)]
= (cosθ + 1) / [sinθ (1 + cosθ)]
= 1 / sinθ
= cosecθ

1. 已知 cos θ = 4/5 , 求1 + tan θ 的值
cosθ = 4/5
sinθ = sqroot(1-(4/5)^2) = sqroot(9/25) = 3/5
tanθ = sin θ/ cosθ = 3/4
1 + tan θ = 1+3/4 = 7/4