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# Trig Question

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Can someone please help me understand how to break this down, this was no where in my homework or lecture but on the test twice?  Sep 19, 2019

#1
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Hello,

The first question:

So, the first question wants us to find a side "x" with a given angle & a side length

and It also gives us that:

x=7cot(39)

so 39 is the angle in (degrees)

well you might be questioning what is 7??

Let's first know cot

cot is co-tangent

We also know that cotangent= Adj/opposite

Let's first find cot(39)

Well we want to solve for x

Since we know that Cot(39)=x/7

Therefore let's multiply both sides by 7

we conclude that:

7*Cot(39)=x

So let's look at triangles..

The correct triangle have the following just from the information we got:

1-the opposite side of the angle is =7

F. is the correct :)

you chose "E." You simply found tangent.

Second question:

Again we have:

4 cos 29

where 29 is the angle in (degrees)

and 4 is a side (We will know soon)

Well first let's know cosine

so let's find the adj side to cos 29

Well it must be "x" because cos(29)=x/4

so multiplying both sides by 4 we get that 4*cos(29)=x

So option E. Is correct. Also notice that X and 4 can't be the opposite side of the angle because cosine is adj/hyp

Hope that helped :) and good luck!

Sep 19, 2019
#2
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You're a life saver thank you!

SoulAbility  Sep 19, 2019
#3
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I tried applying that to another question, and I for the life of me can't understand why the hypotenuse is x on this one.

I'll show you my notes and the question, hopefully you're still around to explain what I did wrong.

Sorry.  SoulAbility  Sep 19, 2019
#4
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From your Q    x=3 hyp/adj  of the angle    x = 3 x/3      of the 42 angle

Sep 19, 2019
#5
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I see where i messed up thx

SoulAbility  Sep 19, 2019
#6
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Don't hesitate to ask questions. :)

Guest Sep 19, 2019
#7
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Just a pattern I noticed:

x=3 sec 42

let it be in that form:

x= r sec z (angle)

sec z= r/f

where f is the adjacent side. (Changes depends on the trigonometric  function etc)

while r is the hypotenus

so r=hyp.

in this case:

x= 3 sec 42

r=3

so x is the adjacent according to the trigonometric function sec hyp/adj

Guest Sep 19, 2019
#8
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Thx, I got it now, aced my test also :D

Pattern I went with made it so easy for me,

I can just take x=7cot(39)

divide the 7 out right away so that x over something = cot(theta)

x/7 = cot39

Then just set trig function what side it represents, in this case adj/op

x/7 = a/o

and it matches up every time x=a and 7=o adjusted to theta

SoulAbility  Sep 19, 2019