Réponse :
cos²(x)+sin²(x) = 1
(3/5)² + sin²(x) = 1
sin²(x) = 1 - (9/25)
sin²(x) = 16/25
x ∈ ]0; π/2[ donc sin(x) > 0
sin(x) = 4/5
tan(x) = sin(x) / cos(x)
tan(x) = (4/5) ÷ (3/5)
tan(x) = 4/3
Explications étape par étape
