jika tan ∅ = 2/5 √5 nilai sin π/2 - ∅ ) = ?

Bab Trigonometri
Matematika SMA Kelas X

tan θ = 2/√5 = y/x
r = √(x² + y²)
r = √(2² + √5²)
r = 3

sin (π/2 - θ) = cos θ

cos θ = x/r = (√5)/3 = (1/3) √5