Question 299938: If x is a acute angle of a right triangle and sinx=3/5, what is the value of cos x
Answer by nyc_function(2741)   (Show Source):
You can put this solution on YOUR website! sine = opposite side of right triangle divided by hypotenuse.
cosine = adjacent side of right triangle divided by hypotenuse.
You were given sinx = 3/5, which tells me that the hypotenuse is 5 and the opposite side is 3.
We use the Pythagorean Theorem from geometry to find the adjacent side.
Let A = adjacent side.
(3)^2 + A^2 = 5^2
9 + A^2 = 25
A^2 = 25 - 9
A^2 = 16
Taking the square root of both sides, we get A = 4.
Like I said before, cosine = adjacent side of right triangle divided by hypotenuse.
Then cosx = 4/5
Understood?
|
|
|
