Question

2cos^2x +sinx-1=0

Answer 1

2(1-sin^x) + siin x - 1= 0

Answer 2

can't we use the quadratic again ?

Answer 3

Yes we can.
solve this.

Answer 4

.5 and -1

Answer 5

use it

Answer 6

\[-2\sin^2 x + \sin x + 1\]

Answer 7

yep

Answer 8

-2y + y + 1 =0

y = 1, y = -1/2

Answer 9

@lgbasallote , ok thanks. will do. -_-

Answer 10

why -2 ? the heck?

Answer 11

calm down bro, it's cos^2x.
cos^2x = (1-sin^x)

Do you remember any identity.

Answer 12

wait so why didn't you change the problem before like this one ?

Answer 13

sin^2x + cos^2x = 1

Answer 14

Because they were same.
here they are different.
They are sin and cos.

in last one they were ONLY cos.

Answer 15

oh yeah, but that still not the answer though

Answer 16

sin x = y


y = 1, y = -1/2


sin x = 1, sin x = -1/2

Solve.

Answer 17

im eating a muffin with milk. yay.

Answer 18

0___0

Answer 19

so 1 and -1/2 is answer or not ?

Answer 20

great! im drinking coke lol

Answer 21

coke is bad for health, milk isn't.

Answer 22

Both are the answers.

Answer 23

milk make me go restroom

Answer 24

That's no good.

Answer 25

what the heck, the answers are pi/2, 7pi/6 and 11pi/6 so why the 1 and -1/2 there? lol

Answer 26

Dont worry man.

there's a simple formula.
\[2 \pi = 360^{*}\]

Answer 27

Therefore,
\[D \times \frac{\pi}{180} = R\]

Answer 28

my calc have to be in degrees or radian?

Answer 29

That's obvious man.

Answer 30

lol, but i still not getting the answer

Answer 31

http://i0.kym-cdn.com/entries/icons/original/000/000/554/facepalm.jpg

Answer 32

1x pi/180 =
LOL

Answer 33

hang in there :|

Answer 34

Do you sleep in class or something?
-just wondering. lol

What? are you leaving?

Answer 35

im don't sleep in class lol, it just that the teacher don't explain very much and i have to learn everything by myself ..... :|

Answer 36

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/156417_370616662973432_235147126520387_918126_1079523894_n.jpg
Lol, check this out.

Answer 37

lol

Answer 38

Can i get a teaching job like that too? :D
where i dont have to teach? ;D

Answer 39

he really confuse im telling you and we only have like 50 mins per class

Answer 40

but now is no time for complain =.=

Answer 41

ok 1 and -1/2

Answer 42

Turn the calc into radian mode.

Answer 43

1 x pi/180 = .0174

Answer 44

what the heck?> :O

Answer 45

http://answers.yahoo.com/question/index?qid=20090312222055AA3FPqb

Answer 46

Dont worry. just chill.

Answer 47

i know that! lol

Answer 48

you search everything so damn fast...

Answer 49

oh. okay. lol.

Haha.

Answer 50

you should learn something that has to do with computer and math at the sametime, you will be billionaire

Answer 51

and i got both autographs..

Answer 52

in rad mode,
\[\sin^{-1} ( 1) \to \frac12 \pi\]

Answer 53

I dont like being rich.
hhe.

Answer 54

oh fk... i totally forgot about the sin part

Answer 55

\[-\sin^{-1}\frac12 \to - \frac16 \pi\]

Answer 56

Lol. Chill pill~.

Answer 57

-1/6pi is not one of the answer...

Answer 58

do you teach private lession ? lol lol

Answer 59

as a matter of fact, you should take sin^{-1}(1/2) you will get 1/6 pi.
moving along, then check out for quadrats where x is negative and so on.

Answer 60

Yes, i dont teach people privately.
i even teach college people in US.
and im teaching people from a year or so..

Answer 61

darn... :|

Answer 62

What's so sad in that? D:

Answer 63

had fun spamming lol

Answer 64

trolling/spamming are fun!
Party scene! :D

Answer 65

i did that but 1/6 is not one of the answer so why are u include it in there?

Answer 66

=.=

Answer 67

are you still ON for like 1 or 2 more hours?

Answer 68

cuz i gtg to a friend house for a bit, but i brb :D with more questions ofcourse

Answer 69

like i said we have look for qudrants and subtract 1/6 from 2pi like we subtract angles from 360 and so on..

Secondly, so you really think im a robot?
lol, im awake from 18 hours and studying math from about 12 hours and im half dead already.
so i will be online but i have some other teaching work to do as well.
But if you want, i can teach you this stuff privately.

you may email me i will come online here then? if that's ok?

Answer 70

I was online just of your trig questions. ;)

Answer 71

what your email then?

Answer 72

einstein.saifoo@gmail.com

Answer 73

wow i knew it haha

Answer 74

LOl.

Answer 75

ok cya :)

Answer 76

Sure.

Answer 77

back :)

Answer 78

damn it i want to play this game i just borrow from friend so badly :|

Answer 79

Welcome.

Answer 80

but i gotta focus on studyyyyy >:O

Answer 81

which game?

Answer 82

Reckoning

Answer 83

i'll play it later :D

Answer 84

Action games.. i dont like..

Sure.

Answer 85

now back to this problem

Answer 86

what game do you like then? :O

Answer 87

The sims? lol

Answer 88

Racing.

Answer 89

naw it's the sims :)

Answer 90

Haha. no.
games like nfs, gta, etc

Answer 91

gosh i love gta

Answer 92

i was gonna borrow from him too but he's not finish with it yet so....:D

Answer 93

ok focus!

Answer 94

Focusing..

Answer 95

-.5 is not one of the answer but 1 is

Answer 96

how do i find the rest of the answer again?

Answer 97

i plugged in sin^-1(1) and got 1.5 which is pi/2 = what i needed

Answer 98

now i need to know how they got 7pi/6 and 11pi/6