Question

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I believe it is cos y, am I correct? I don't really understand trigonometry very well.

Answer 1

@jim_thompson5910 Hey, do you know how to do this?

Answer 2

what do you think is the answer?

Answer 3

I think it's cos y

Answer 4

Just label the sides a, b and c, so you can easily be sure. You should be 100% sure.

Answer 5

I'm not sure what to do once I label them that way though, as I said I'm really bad at trigonometry so forgive me if I sound ignorant on this it's just that I honestly am

Answer 6

Of sides a, b, c, which ones are the legs and which one is the hypotenuse?

Answer 7

B is the adjacent, and A is the hypotenuse

Answer 8

C is the hypotenuse*

Answer 9

A would be the opposite

Answer 10

In the triangle, a and b are legs.
c is the hypotenuse.
Ok so far?

Answer 11

Mhm!

Answer 12

You can only call legs adjacent and opposite once you choose which acute angle you are referring to.
The problem starts with by using cos x.
Let's also use angle x for now.
We need the cos x.
For cos x we need the adjacent leg and the hypotenuse with reference to angle x.

\(\cos x = \dfrac{adj}{hyp} \)

For angle x, which leg is the adjacent leg, a or b?

Answer 13

I believe B

Answer 14

You wrote above b is adjacent, and you were correct with reference to angle x.

Answer 15

Now we can write what cos x is equal to.

\(\cos x = \dfrac{b}{c} \)

Ok so far?

Answer 16

Mhm!

Answer 17

Sorry. I'm getting tired.
The problem starts with sin x, not cos x.

\(\sin x = \dfrac{opp}{hyp} \)

so

\(\sin x = \dfrac{a}{c} \)

Answer 18

Forget about cos x.
We start with what the problem tells us.

\(\sin x = \dfrac{a}{c} \)

Answer 19

Opposite, I believe

Answer 20

Side a is right next to angle y, so side a is adjacent to angle y.
Looking at angle y, a is the adjacent leg.
With reference to angle y, \(\dfrac{a}{c} \) is adj/hyp which is the cosine.

Answer 21

I see, so my first response was right?

Answer 22

Yes, you were correct all along, but I hope that now you understand why.
When you change the reference angle of the acute angle of a right triangle, the adjacent and opposite legs switch.

Answer 23

Got it, makes sense!! Thank you so much for the help, I appreciate it :)