jika tan 0=2/5√5,nilai sin (π/2-0)=

Bab Trigonometri
Matematika SMA Kelas X

tan A = (2/5) √5 = 2/√5 = y/x

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

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