Question

I need help with Part B. view attached picture.

Answer 1

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

Answer 2

<R=42 <S=44, I believe

Answer 3

is the arc RS = arc ST?

Answer 4

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.

Answer 5

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

Answer 6

yes.

Answer 7

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

Answer 8

but i dont know SR or RT

Answer 9

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

Answer 10

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.

Answer 11

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

Answer 12

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

Answer 13

i'm in geometry.

Answer 14

have you ever done solving of equations?

Answer 15

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.

Answer 16

3x = 21
what is x?

Answer 17

x=7

Answer 18

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

Answer 19

3?

Answer 20

how did you get that?

Answer 21

so would the answer be 2?

Answer 22

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

Answer 23

21 times 3 is 7?

Answer 24

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

Answer 25

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

Answer 26

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

Answer 27

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

Answer 28

\[...\]

Answer 29

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

Answer 30

it would be 44 and 46.

Answer 31

sorry.

Answer 32

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

Answer 33

r is 46

Answer 34

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

Answer 35

i know Pythagorean theorem.

Answer 36

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

Answer 37

sin of 46 = .7193398003

Answer 38

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

Answer 39

which is 30.58359051

Answer 40

\[30.6 rounded\]

Answer 41

okay great. so what is the radius?

Answer 42

15.3

Answer 43

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

Answer 44

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

Answer 45

lol, no.

Answer 46

haha. Well Thank You.

Answer 47

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

Answer 48

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

Answer 49

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

Answer 50

yeah.

Answer 51

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,.

Answer 52

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. :(

Answer 53

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 =?

Answer 54

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

Answer 55

i understand.

Answer 56

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

Answer 57

in other words, RT = 22/sin42

Answer 58

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.