Question

Does anyone know the answer for the question below.

Answer 1

Answer: option C

Step-by-step explanation:

The diagram of the triangle is shown in the attached photo. The triangle is a right angle triangle ABC

Assuming the given angle is #,

Recalling the trigonometric ratio,

tan # = opposite / adjacent

If tan # = 4, it means

opposite / adjacent = 4/1

Therefore, opposite = 4 and adjacent = 1

Applying Pythagoras theorem,

Hypotenuse^2 = opposite ^2 + adjacent ^2

Hypotenuse = AC

Opposite = 4

Adjacent = 1

AC^2 = 4^2 + 1^2 = 17

AC = ± √17

To determine cos #, we would apply another trigonometric ratio,

Cos# = adjacent /hypotenuse

Cos# = 1/±√17

Cos # =-1 /√17 or 1/√17