Question

HURRY! 6 MIN LEFT!!!

Given right triangle JKL, what is the value of cos(L)?

A). 5/13
B). 5/12
C). 12/13
D). 12/5

Answer 1

A. 5/13 is the right answer.

Answer 2

Answer: A.
`\cos L=(5)/(13)`

Explanation:

For angle y in a right triangle ,the trigonometric ratio of cos y is given by :-

`\cos y=\frac{\text{side adjacent to y}}{\text{Hypotenuse}}`

Given: The side adjacent to angle L= 5 units

The side opposite to angle L = 12 units

Let h be the hypotenuse, then using Pythagoras in the given right triangle, we get

`h^2=12^2+5^2\\\\\Rightarrow\ h^2=144+25\\\\\Rightarrow\ h^2=169\\\\\Rightarrow\ h=√(169)=13`

Thus, hypotenuse = 13 units

Now, the trigonometric ratio for cos L is given by :-

`\cos L=\frac{\text{side adjacent to L}}{\text{Hypotenuse}}\\\\\Rightarrow\cos L=(5)/(13)=(5)/(13)`

Hence, the value of cos L =
`(5)/(13)`