Tan β = √5 β sudut lancip maka sec β adalah...

Misal:
x = samping
y = depan
r = miring (hipotenusa)

Pembahasan:
tan = de/sa = y/x = √5/1

Cari "r" maka,
r² = √5² + 1²
r² = 5 + 1
r² = 6
r = √6

Maka sec β:
= miring/sampin
= r/x
=√6/1
= √6