Let α∈ (0, π / 4), sin α + cos α = 7 / 5, then Tan α=___

Let α∈ (0, π / 4), sin α + cos α = 7 / 5, then Tan α=___

Let α ∈ (0, π / 4), sin α + cos α = 7 / 5,
Sin ^ 2 α + cos ^ 2 α = 1, Sina = 3 / 5, cosa = 4 / 5 or Sina = 4 / 5, cosa = 3 / 5
α∈(0,π/4),cosa>sina
So Sina = 3 / 5, cosa = 4 / 5
tana=sina/cosa=3/4

Let's know that f (a) = sin (A-2 / π) cos (3 π / 2) Tan (7 π - a) / Tan (- a-5 π) sin (A-3 π) please
(1) Simplify f (a) (2) if Tan (A-3 π / 2) = - 2, find the value of F (a)

(1) (a) cos (3 π / 2-A) Tan (7 π - a) / Tan (a-5 π) sin (A-3 π) or (a-5 π) sin (A-3 π) - cosa (a) (Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / [(Tana) / (a) / [(a) / [(a) / [(Tana) / (a) = (COSA (2) cosa (2) cosa (2) cosa (2) Tana = 1 / 2 (Tana = 1 / 2) Tana = 1 / 2 / 2 (1 / 2) Sina = 1 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 / 2 (or 2 √ 5 / 5

How to judge the tan cos sin of an angle
The angle is between 0 - π ~ give the range of Tan larger than COS and the range of Tan larger than sin and sin larger than cos ~ don't use calculator~
sorry. It's 0-2 π. I have the wrong number. -- I'm terribly sorry.

1）sinx-cosx=√2[sin(x-π/4)],x-π/4∈(-π/4,3π/4),
Obviously, if x ∈ (0, π / 4), then √ 2Sin (x - π / 4) cosx
2)tanx-cosx=[sinx-(cosx)^2]/cosx=[(sinx)^2+sinx-1]/cosx.
x∈（0,π/2）∪（π/2,π),0