Question

Express cos r as a fraction in simplest terms

Answer 1

`(5)/(13)`

Explanation:

If you have studied trigonometry, you will know that
`cos(\theta )=(adjacent)/(hypotenuse)`, where the adjacent is the side with both the right angle and the angle θ, and the hypotenuse is the diagonal side.

We know here that the hypotenuse is 26.

We know do not know that adjacent where both angle R and the right angle are, but we can find it using Pythagoras' Theorem, something else which you may have studied.


`a^2=c^2-b^2\\a^2=26^2-24^2\\a^2=100\\a = √(100)=10`

We now know that the adjacent is equal to 10.

Therefore, we substitute them into the cos ratio, and simplify the fraction.

`cos(R)=(10)/(26) =(5)/(13)`