OpenStudy (anonymous):

I need help with Part B. view attached picture.

6 years ago
OpenStudy (anonymous):
6 years ago

OpenStudy (anonymous):

are x^2+30 and 5x+24 RV and VT correspondingly?

6 years ago
OpenStudy (anonymous):

<R=42 <S=44, I believe

6 years ago
OpenStudy (anonymous):

is the arc RS = arc ST?

6 years ago
OpenStudy (anonymous):

i dont know, i know that angle s is 90 i know that angle r is 42 and that t is 44. sorry i know i screwed up before.

6 years ago
OpenStudy (anonymous):

you need help with the second part, is that right?

6 years ago
OpenStudy (anonymous):

yes.

6 years ago
OpenStudy (anonymous):

since angle S is 90, RST is a right angle triangle so sin <R = ST/RT ( opposite side /hypotenuse) hypotenuse is the diameter. you know <R and ST

6 years ago
OpenStudy (anonymous):

but i dont know SR or RT

6 years ago
OpenStudy (anonymous):

you said <R = 42 right? so sin 42 = ST/RT ST is given in the problem as 22 so sin 42 = 22/RT find out RT

6 years ago
OpenStudy (anonymous):

but i dont understand how to find the denominator. okay so 42=22/x. how do i find x? like what do i do to find it.

6 years ago
OpenStudy (anonymous):

sin 42 = 22/RT multiply both side by RT RT sin 42 = 22 divide both sides by sin42 RT = 22/sin 42

6 years ago
OpenStudy (anonymous):

this is basic equation manipulation. You should know this sort of stuff before you get into trigonometry

6 years ago
OpenStudy (anonymous):

i'm in geometry.

6 years ago
OpenStudy (anonymous):

have you ever done solving of equations?

6 years ago
OpenStudy (anonymous):

yes, but not with solving with sin, cos, and tan. i did basic sin cos and tan like finding what the tan of 22 was etc but nothing like this.

6 years ago
OpenStudy (anonymous):

3x = 21 what is x?

6 years ago
OpenStudy (anonymous):

x=7

6 years ago
OpenStudy (anonymous):

right so 21(sin x) = 7 what is sin x?

6 years ago
OpenStudy (anonymous):

3?

6 years ago
OpenStudy (anonymous):

how did you get that?

6 years ago
OpenStudy (anonymous):

so would the answer be 2?

6 years ago
OpenStudy (anonymous):

because \[21(\sin x) = 7\] \[21*3=7\]

6 years ago
OpenStudy (anonymous):

21 times 3 is 7?

6 years ago
OpenStudy (anonymous):

Sorry I know im hopeless. no 21/3 (duhhh)

6 years ago
OpenStudy (anonymous):

21 sin x = 7 divide by 21 on both sides 21sin x / 21 = 7/21 sin x = 1/3

6 years ago
OpenStudy (anonymous):

okay i understand. its because 7 is 1/3 of 21.

6 years ago
OpenStudy (anonymous):

right. exactly so sin x = 1/3 which means that \[x = \sin^{-1} (1/3)\]

6 years ago
OpenStudy (anonymous):

\[...\]

6 years ago
OpenStudy (anonymous):

you made a mistake somewhere. if <S = 90 then <R and <T cannot be 42 and 44.

6 years ago
OpenStudy (anonymous):

it would be 44 and 46.

6 years ago
OpenStudy (anonymous):

sorry.

6 years ago
OpenStudy (anonymous):

right. so what is <R? 44 or 46?

6 years ago
OpenStudy (anonymous):

r is 46

6 years ago
OpenStudy (anonymous):

okay so sin 46 = ST/RT ----> RT = 22/sin 46 use your calculator to find RT. do you know pythagoras theorem?

6 years ago
OpenStudy (anonymous):

i know Pythagorean theorem.

6 years ago
OpenStudy (anonymous):

also check out khanacademy for help understanding all these concepts. http://www.khanacademy.org/

6 years ago
OpenStudy (anonymous):

sin of 46 = .7193398003

6 years ago
OpenStudy (anonymous):

right so 22/0.71934 is the hypotenuse. which happens to be the diameter of your circle

6 years ago
OpenStudy (anonymous):

which is 30.58359051

6 years ago
OpenStudy (anonymous):

\[30.6 rounded\]

6 years ago
OpenStudy (anonymous):

okay great. so what is the radius?

6 years ago
OpenStudy (anonymous):

15.3

6 years ago
OpenStudy (anonymous):

there you go. you have your answer. although you should calculate the radius first and then round it

6 years ago
OpenStudy (anonymous):

Thank You So Much! May I ask are you Salman Khan?

6 years ago
OpenStudy (anonymous):

lol, no.

6 years ago
OpenStudy (anonymous):

haha. Well Thank You.

6 years ago
OpenStudy (anonymous):

you are welcome. make sure you see some videos on equations and how to manipulate them on khanacademy. you will understand these things better,

6 years ago
OpenStudy (anonymous):

yes. how did you find out about khanacademy.com?

6 years ago
OpenStudy (anonymous):

Here. someone referred me to it. I found them pretty useful to explain stuff to other kids.

6 years ago
OpenStudy (anonymous):

yeah.

6 years ago
OpenStudy (anonymous):

math is very simple once you understand what it is you are trying to do. It is simply a tool to solve real life problems using equations and stuff which you can write down. In other words, it is a language to understand problems and convey them to others,.

6 years ago
OpenStudy (anonymous):

I love math, and by my senior year i will be taking AP stats, but this chapter has really started to turn me away from math, because it has taken so long, and i dont really have resources to fully help me. :(

6 years ago
OpenStudy (anonymous):

for example, I can say three times a number is twenty one. what is the number? writing this in english is tedious. so I simply say 3x =21, x =?

6 years ago
OpenStudy (anonymous):

in english, I would say if three times a number is 21, then seven must be the number because three times seven is twenty one, or I can simply write 3x = 21 x = 21/3 = 7

6 years ago
OpenStudy (anonymous):

i understand.

6 years ago
OpenStudy (anonymous):

sinx and cos x and tan x are no different sin 42 = 22/RT simply means sine of 42, which is a number , is equal to the ratio of the number 22 and the number RT. What is RT? RT is the ratio of the number 22 and the number sin 42

6 years ago
OpenStudy (anonymous):

in other words, RT = 22/sin42

6 years ago
OpenStudy (anonymous):

don't get intimidated by the fact that it is sin x or cos x or tan x. treat them like numbers. all the arithmetic operations are valid on them too.

6 years ago