Question

Can someone please help me with this geometry equation?


use the triangle to find the value for cos Ɵ

Answer 1

https://byuis.brainhoney.com/Resource/13385724,6C3,0,0/Assets/Media/Images/GEOM043_CSR1-23.jpg

Answer 2

here is the picture ^^^

Answer 3

Are you familiar with SOHCAHTOA?

Answer 4

do you know the definition for cos

Answer 5

no, can you remind me?

Answer 6

sin = opp/hyp cos adj/hyp

Answer 7

you have the lengths for opp which is 5

and adj is 3

do you know how to find the hypotenuse

Answer 8

pythagoran therom?

Answer 9

No, that's why I asked about SOHCAHTOA

Sine = Opp/Hyp

Cosine = Adj/Hyp

Tangent = Opp/Adj

They are just special ratios in right triangles

Answer 10

yes
(opp)^2 + (adj)^2 = (hyp)^2

go ahead and plug in you values and solve for hyp

then take adj/hyp=cos theta

Answer 11

@zpupster Why are you telling @Kanine123 to solve for the hypotenuse? You can use the inverse function of the Tangent of Theta to find its value

Answer 12

yes that is another way

Answer 13

tan^-1 (theta) = (5/3)

Answer 14

wait but if you used the Pythagorean theorem and got root 34 for the hypotenuse. would the answer not 3/ root 34?

Answer 15

@Kanine123 Remember the question is asking for the value of the angle theta, not the hypotenuse, you didn't have to look for the hypotenuse, you don't need that info. in this problem

Answer 16

use the triangle to find the value for cos Ɵ

Answer 17

wait but i dont understand, to find the value for cos dont you need the hypotenuse?

Answer 18

maybe pablo can help you i have ot run

Answer 19

@Kanine123 This problem does not require any cosines, you need the tangent of theta. This is where SOHCAHTOA comes in handy. TOA, so tangent = opposite over adjacent

Answer 20

okay so the tangent is 5/3.

Answer 21

Yeah, so now we know that angle theta has a tangent equal to 5/3 which is roughly 1.6666 repeating. Now we ask ourselves, what angle has that theta ratio? We use a calculator and we type in:

Tan-^1( 5/3)

Answer 22

59.036233 degrees?

Answer 23

Yeah, that's it. Great! Sometimes we think we have to do extra steps to solve the problem, but that's not necessary xD And remember SOHCAHTOA, it's super handy :D

Answer 24

awesome! thanks a bunch