Use the image below to answer the following question. Find the value of sin x° and cos y°. What relationship do the ratios of sin x° and cos y° share?
Help Me Please Im Really Behind
@ganeshie8 @amistre64 @mathmale
I only have this and another question left
woow, i dont know this yet sorry :)
Im in 10th grade
First, some basics: Knowing the definitions of the sine and cosine function is essential. What are these definitions? For example: \[\tan x = \frac{ opposite~side }{ adjacent~side }\]
Write out similar definitions for the sine and cosine of the angle x.
Sine is opposite/ hypotenuse and cosine adjacent/ hypotenuse and if they equal 90 they must be complemantary angles
Next: Note that x and y are "complementary angles." What does that mean to you?
That they equal to 90 degrees
Nice work; just a little tweak to the wording: If the SUM of x and y is 90 degrees, then x and y are complementary angles. (You must mention the word "sum.")
Ok
Now look at angle x. Which side of this triangle is "opposite" angle x? Which side is the hypotenuse? Knowing these two values, find the ratio opp side sin x = -------------- hyp
which must be a fraction between 0 and 1.
Sin x = 3/4
is that it?
No, unfortunately. Your 3/4 is the TANGENT of the angle x. You correctly defined the SINE of angle x. Find sin x using the appropriate side lengths given in the figure.
If the 2 "legs" of this triangle are 3 and 4 respectively, what is the length of the hypotenuse? Hint: use the Pythagorean Theorem to find the length of the hyp.
Umm lets see
Those trig functions and the Pyth Theorem are extremely important and are worth memorizing and practicing.
a*2 + B*2 = C*2 3*2 + 4*2 = C*2 9 + 16 = C*2 25 = c*2 c = 5
is this correct
yes, the length of the hyp is 5. So the sine of x is what fraction?
Sin x = 3/5
Great. Got it. For review: What is the definition of the cosine function?
What is cos x? What is cos y?
cosine is adjacent/hypotenuse
4/5
cos x = 4/5
Great. That's the definition. Now, what is cos x? Right you are. Now, what is cos y?
cos y ? umm im a little confused what is cos y?
The principle is exactly the same. Find angle y. Identify its adjacent side and its hypotenuse. Write the cosine of y exactly as you did before: cos y = adj / hyp
So it would be cos x = 4/5
So this would mean that my answer is sin x = 3/5 and cos y = 4/5 correct
And that there relationship would be that there sum is to 92 degrees meaning that there complemantary correct?
90 degrees my bad
@mathmale
@amistre64 can you help me finish up
@ganeshie8
Anyone
@phi
@phi mathmale is offline I just need to know if its correct
where are you in the question ?
. Find the value of sin x° and cos y° you should get the same ratio for these.
Sorry umm we are done with the question I just need to know if its correct
to do this use the definitions (people use SOH CAH TOA to remember them) sin use SOH: sin= opp/hyp sin x means put your finger on the x angle. go "across" to the other (i.e. opposite ) side and read off 3 as you know , they hypotenuse is 5, you get sin x = 3/5 I
Yes and cos is cos x = 4/5
There complemantary which means that they sum up to 90 degrees thats there relationship that they share together.
now do cos y° cos: CAH cos= adjacent/hyp put you finger on angle y. Find the adjacent side . It is the side that makes up part of the angle but is NOT the hypotenuse. You should find 3 cos y = 3/5
I got it now. Can you help me with one last question please.
An observer (O) is located 660 feet from a tree (T). The observer notices a hawk (H) flying at a 35° angle of elevation from his line of sight. How high is the hawk flying over the tree? You must show all work and calculations to receive full credit.
you found cos x , but they want cos y
if you are doing a different question, pleasemake a new post.
arent cos x and y the same thing
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