Question

what is the domain of validity for the trigonometric identity cscθ=1/sinθ HELP PLEASE

Answer 1

@jim_thompson5910 @amistre64 I've been stuck on this problem for so long and I really need the answer to this and a few others!

Answer 2

I don't know @jim_thompson5910

Answer 3

sin? theta? i'm really not sure

Answer 4

0? I don't know. There aren't numbers in the equation..

Answer 5

I don't know how to do that.. Sorry, I've been doing math homework all day and my brain is kind of fried, lol.

Answer 6

I'm sorry, I don't know how to write the problem and do it in order to solve it. I suck at math.

Answer 7

No

Answer 8

my computer isn't loading the page

Answer 9

all real numbers except multiples of pi, because that's when the denominator would equal 0 (csc = 1/sin)

Answer 10

thank you :D @mangorox

Answer 11

No problem @icedancerfigureskater

Answer 12

Can I have help with just a few more? @mangorox

Answer 13

I'll try to help

Answer 14

Ok. What is the radian measure of an angle whose tangent is -0.25? My answers are: -1.33, 0.24, 2.9, and 4.95

Answer 15

@mangorox

Answer 16

Ok let me see...

Answer 17

i'm sorry I don't know the answer to this question :(

Answer 18

It's okay, do you think you can help me with a question using unit circles and inverse functions? @mangorox

Answer 19

I can try, it depends on the question.

Answer 20

Okay. Use the unit circle to find the inverse function value in degrees. cos^-1 (sqrt3/2)

Answer 21

Does this help?: the unit circle can help you find the correct quadrants, but you have to memorize the actual degrees.

You should know the sin, cos and tan of
0º, 30º, 45º, 60º, and 90º

there is a pattern for sin:
0 1/2 sqrt(2)/2 sqrt(3)/2 1

if we use sqrt(0) is 0 and sqrt(1) is 1 and the sqrt(4) is 2,
the pattern is
sqrt(0)/2 sqrt(1)/2 sqrt(2)/2 sqrt(3)/2 sqrt(4)/2

cosine goes in the other direction
tangent is sin/cos

Answer 22

Kind of, but I don't know how to get my answer

Answer 23

ok
what is the sin(60º) ?

the answer is : memorize it. See above.
it is a number between -1 and 1. In this case 0.866025403... and on and on
rather than type all the numbers people give the equivalent sqrt(3)/2

type
sin(60 degrees)=
in the google search window. It will give you that number

type
sqrt(3)/2=
in the google search window. It will give the same number

Answer 24

This might help also: http://www.khanacademy.org/math/trigonometry/v/basic-trigonometry

Answer 25

the answer they want (I am assuming) is
sin−1(3√2)=60º and 120º

Answer 26

the answer is 60 degrees, thank you.

Answer 27

No problem!

Answer 28

Do you know how to solve this one? @mangorox

Simplify the trigonometric expression. sin^2 θ /1-cosθ

Answer 29

Sorry, I don't know how to solve that one

Answer 30

Ok, that's fine.

Answer 31

17. Verify the pythagorean identity. 1+cot^2 θ =csc^2 θ

@DLe @mangorox @jim_thompson5910 @amistre64 @dan815

Answer 32

cot^2 θ = (cos^2 θ) / (sin^2 θ)

so,

1 + (cos^2 θ) / (sin^2 θ) = [sin^2 θ + cos^2 θ] / (sin^2 θ) = 1 / (sin^2 θ) = csc^2 θ

qed

Answer 33

Thank you! @mangorox I only have one more that I need help with if you can.

18. Verify the identity.

tan θ + cot θ = 1/ sinθ cosθ

Answer 34

tan A + cot A =?= 1/(sinA cosA)

tan A = sinA / cosA
cot A = cosA / sinA


So, sinA/cosA + cosA/sinA = 1/(sinAcosA)

multiply both sides by sinAcosA

sinAcosA (sinA/cosA) + sinAcosA(cosA/sinA) = 1

sin^A + cos^2A = 1

Answer 35

Thank you so very much!!! @mangorox

Answer 36

No problem! :) @icedancerfigureskater