Question

Advance Trig Help

Answer 1

Prove the identities

sin(theta)=4/5

Answer 2

Find the five other trigonomic values for (theta)

Answer 3

well. you know that sin is y/r
with r being the hypotenuse

Answer 4

And y is the opp?

Answer 5

yes. but since you dont have an angle to work with we dont care about opposite for this problems. just in terms of x y and r

Answer 6

so draw your triangle with the y as 4 and they hyp as 5 and it should be obvious

Answer 7

Oh. So what it means by other values is the degrees and other sides?

Answer 8

umm hmm. no you just make a triangle. find all three sides. and write them in terms of x y and r
sin is y/r
cos is x/r
tan is y/x
csc is r/y
sec is r/x
cot is x/y

Answer 9

so you know the y and r. use the pythagorean theorem x^2+y^2=r^2
to get your x value

Answer 10

(2)^2+(4)^2=r^2?

Answer 11

uhh. where did the 2 come from. it was 4/5 with 5 being r and 4 being y

Answer 12

lol, ops

Answer 13

x^2+4^2=5^2

Answer 14

x^2+4^2=1^2?

Answer 15

pythagorean triple. but if your already confused i would ignore what i just said

Answer 16

where did the 1 come from?

Answer 17

it should be a 5 lol.

Answer 18

Im getting the radius of the circle mixed up x_x

Answer 19

y/r , y=4 r=5 ?

Answer 20

x^2+4^2=5^2?

Answer 21

yes.

Answer 22

So its 3?

Answer 23

x is 3 now you know x y and r and knowing your ratios in terms of x y and r you can fill all of them now

Answer 24

Wow! It seems much easier that way

Answer 25

yes, indeed. it is easy.

Answer 26

sin is 4/5
cos is 3/5
tan is 4/3
csc is 5/4
sec is 5/3
cot is 3/4

Answer 27

perfect.

Answer 28

Wait a minute...

Answer 29

Somethings not right..

Answer 30

How would I know the combinations for sin,cos,tan,csc,sec, and cot?

Answer 31

Do I have to memorize them?

Answer 32

you will have to in terms of x y and r opp adj hyp and the unit circle definitions

Answer 33

Thats over 6 diff combinations @_@

Answer 34

its easy. just remember sin cos and tan. and the others are reciprocals.

Answer 35

k

Answer 36

At least I know what to work on, lol.

Answer 37

ya. get on pauls online math notes and print off his trig cheat sheet. will save your life if you memorize all the identities and the unit circle and all the function definitions.

Answer 38

Fore Sure.

For the next question

Find the six trigonometric values of the angle whose terminal side lies on the point

(3,-5)

Answer 39

Isnt it the same thing?

Answer 40

can you tell me what quadrant that is in?

Answer 41

and. it is not the same thing.

Answer 42

Quadrant?

Answer 43

uuuuuuh ya the quadrants. you dont know the quadrants? 1-2-3-4?

Answer 44

Oh, you are testing me. I thought you were asking for more info on the question

Answer 45

ya. where does that point lie on the rectangular coordinate system

Answer 46

quadrants 1 and 2?

Answer 47

you know the x is 3 and the y is -5.
and no it would be in quadrant 4.

Answer 48

Pos Pos, and neg neg qaudrents

Answer 49

use the pythagorean theorem on the x and y to get r. then write out all of the rest

Answer 50

with 3,-5 you will be facing down to the right on the grid. into quadrant 4 where your x value is positive and your y value is negative.

Answer 51

Im misunderstanding all of your questions. It must be frustrating. Srry.....

Answer 52

im not frustrated at all. im terrible at wording and explaining stuff.

Answer 53

so knowing what you know now. what do you have for r

Answer 54

So 3^3+-5^2=r^2?

Answer 55

yes

Answer 56

so 9+25=r^2?

Answer 57

yes

Answer 58

34=r^2

sqrt(34)=r?

Answer 59

yes.

Answer 60

Are the six trig values the ones from before? Soo all we need to do now is plug in?

Answer 61

sin-y/r
cos-x/r
tan-y/x
csc-r/y
sec-r/x
cot-x/y
now plug and chug. i always rationalize denominators also.

Answer 62

sin- -5/(sqrt)34
cos- 3/(sqrt)34
tan- -5/3
csc-sqrt(34)/-5
sec-sqrt(34)/3
cot- 3/-5

Answer 63

keep in mind your in quadrant 4 and what your signs will be
in 1 all pos
in 2 students(sin) positive
in 3 take(tan) positive
in 4 calculus(cos) positive

Answer 64

ya, as long as you dont have to rationalize the denominators, that is correct.

Answer 65

k

Answer 66

Find the value of (theta)

cot(theta)=1

Answer 67

inverse cot to both sides.

Answer 68

cot^-1(1)

Answer 69

cot^-1(1)=theta

Answer 70

What os theta though?

Answer 71

theta will be whatever your calculator spits out for the input i posted above.

Answer 72

inverse tan (1) or arctan

Answer 73

Itsna little bit harder to type since im using my phone

Answer 74

well. if you wanna do it on paper. you know that when tan or cot is positive 1 you are in quadrant 1 or 3 at a 45 degree angle, right?

Answer 75

so your possible angles are 45 and 225

Answer 76

k

Answer 77

do you see how i did that? if cot is positive 1 its q1 or 3. theyre 1 whenever you have a 45-45-90. making cot45=1 and the reference angle 45 from the x axis is 1 as well.

Answer 78

So theta is a variable then?

Answer 79

yes. you solve for it using inverse operations. just like an algebra problem.

Answer 80

What about sin(theta)=1/2?

Answer 81

You would inverse to have

sin(1)^-1=theta?

Answer 82

do you want theta or the 6 trig functions?
if you want theta, of course use inverse sin

Answer 83

, I want the value of theta

Answer 84

Im still a bit confused on this one. How wouls you get a number that equals theta? Is it just degrees?

Answer 85

if your calculator is in degrees it will.

Answer 86

Wait... woudnt it be sin(30)=1/2?

Answer 87

yes. now your getting the feel for your 30 60 90 triangles.

Answer 88

Now on to the last ones

Answer 89

FInd the amplitude,range,and domain of y=cos((1/2)x)-2

Answer 90

you you know which numbers do what to the graph?

Answer 91

I know that amplitude is similar to an asymtote

Answer 92

2pi/p

Answer 93

hmmmm. amplitude is the height of the graph. it is whatever is in front of cos

Answer 94

p/4

Answer 95

multiplied to cos that is.

Answer 96

amplitude is 1

Answer 97

2pi/(1/2)=period?

Answer 98

that is correct for period