Question

In triangleABC, C is the right angle. If tanA = 8/6, find cosB

A. 6/8
B. 6/10
C. 8/10
D. Doesnt exist

Answer 1

Short answer = C) 8/10

Working :

Tan A = 8/6 = Opposite / AdjacentOpposite = 8 units

Adjacent = 6 units

Hypotenuse =
`\sqrt{8^(2) + 6^(2) }`

=
`√(64 + 36 )`

=
`√(100)`

= 10 units

Cos B = Adjacent/ Hypotenuse

∴ cos B= 8/10