jika tan teta = 2/5√5, nilai sin (π/2-teta) =… A. 1/3√5 B. 2/3√5 C. 2/5√5 D. 3/5√5 E. 2/3

Bab Trigonometri
Matematika SMA Kelas X

tan θ = (2/5) √5 = 2/√5 = y/x

r = √(x² + y²)
r = √((√5)² + 2²)
r = √(5 + 4)
r = √9
r = 3

sin (π/2 - θ)
= cos θ
= x/r
= (√5)/3
= (1/3) √5

◎◎ A ◎◎