Question

Find the value of the Cosine
A
B
C
D

Answer 1

The cosine for ∠A is
`(5√(89) )/(89)`.

Option: A.

Explanation:

From the given diagram,

Opposite = 8 ft.

Adjacent = 5 ft.

In trigonometry, the formula for cosine =
`(adjacent)/(hypotenuse)`.

We are not given with hypotenuse. So we have to find the hypotenuse using Pythagorean Theorem
`hypotenuse = √(opposite^2+adjacent^2)`

`hypotenuse = √(8^2+5^2)`.

`hypotenuse = √(64+25)`.

hypotenuse =
`hypotenuse = √(89)`.

cosine =
`(5)/(√(89) )`.

Multiply
`√(89)` in both numerator and denominator,

The cosine for ∠A is
`(5√(89) )/(89)`.