The Help CodeDude study for his math test THREAD *UPDATED NEW QUESTION*

[MrCodeDude]

Question #2
Find all solutions of the equation in the interval [0, 2pi)

ANSWER IS :: pi/2, 3pi/2


help?

I get an answer that way, but it's not the correct answers 🙁
-- mrcodedude

 

[venk]

Is this a proof? Solving for X? BTW, your step two is wrong. It should be cos x (2 cos x - 1) = 1

 

[jacob0401]

What math is this?

I have similar math test tomorrow...radians and trig...

 

[Kev]

it's been about 3 years since i've had math but i know you cant do it that way. there are different things that equate to cosine squared, you should look them up in your book and try substitution

 

[Syringer]

Originally posted by: venk
Is this a proof? Solving for X?

 

[MrCodeDude]

It's a trig identity. Find all solutions of the equation in the interval [0, 2pi).
-- mrcodedude

 

[Syringer]

Is the answer x = pi/6?

 

[MrCodeDude]

The answer is: 0, 2pi/3 and 4pi/3
-- mrcodedude

 

[3L33T32003]

I guess you are screwed.

 

[Martin]

cos x =1
or
cos x = 1/2

There fore
x = 0, pi/3 and others, depeding on what the range is..

 

[OREOSpeedwagon]

Originally posted by: 3L33T32003
I guess you are screwed.

lol 😀

 

[Syringer]

Originally posted by: MartyTheManiak
cos x =1
or
cos x = 1/2

There fore
x = 0, pi/3 and others, depeding on what the range is..

If you plug in pi/3 into the equation it doesn't work..

 

[MrCodeDude]

Originally posted by: MartyTheManiak
cos x =1
or
cos x = 1/2

There fore
x = 0, pi/3 and others, depeding on what the range is..

That's what I got, but the book says otherwise 🙁
-- mrcodedude

 

[venk]

It should be x*pi/3 where x is every even number in the range.

 

[MrCodeDude]

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

 

[eLiu]

set x=cosx

then you have 2x^2-x-1=0
Solve the quadratic equation...and substitute cosx back and use the arccos function to find the answers
-Eric

 

[imported_Mike]

whats with all the "do your own hw" retards. Its one problem....id like to know in advance which teachers give out 1 problem hw sets to do over the weekend...

 

[MrCodeDude]

Originally posted by: eLiu
set x=cosx

then you have 2x^2-x-1=0
Solve the quadratic equation...and substitute cosx back and use the arccos function to find the answers
-Eric

Yeah, that worked. Thanks 🙂

Because that way you get
cos x = 1 ; cos x = -1/2
😀
-- mrcodedude

 

[Syringer]

Originally posted by: eLiu
set x=cosx

then you have 2x^2-x-1=0
Solve the quadratic equation...and substitute cosx back and use the arccos function to find the answers
-Eric

Hmm, that worked.

x = 1, x = -1/2

cos x = 1
x = 0

cos x = -1/2
x=2pi/3

 

[3L33T32003]

Originally posted by: MrCodeDude

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

Oh, I am sorry did I offend you?

I tried to help again, but
nobody was home.

 

[Syringer]

Originally posted by: venk
Is this a proof? Solving for X? BTW, your step two is wrong. It should be cos x (2 cos x - 1) = 1

AHHH, yeah I was doing that same mistake..

 

[Kev]

Originally posted by: 3L33T32003

Originally posted by: MrCodeDude

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

Oh, I am sorry did I offend you?

I tried to help again, but
nobody was home.

that was pretty lame, but thanks for the effort

 

[Syringer]

Originally posted by: maladroit

Originally posted by: 3L33T32003

Originally posted by: MrCodeDude

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

Oh, I am sorry did I offend you?

I tried to help again, but
nobody was home.

that was pretty lame, but thanks for the effort

There was effort involved in that?

 

[3L33T32003]

Originally posted by: maladroit

Originally posted by: 3L33T32003

Originally posted by: MrCodeDude

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

Oh, I am sorry did I offend you?

I tried to help again, but
nobody was home.

that was pretty lame, but thanks for the effort

Yah well, the last time I took an hour out of my life and did something for this guy he did not even send me a thank you note. So from now on he gets flamed when he asks for free help from his "friends" here at atot.

 

[Howard]

Originally posted by: 3L33T32003

Originally posted by: maladroit

Originally posted by: 3L33T32003

Originally posted by: MrCodeDude

Originally posted by: 3L33T32003
I guess you are screwed.

Hey asshole, have you ever not gotten the correct answer on a problem? I attempted to solve the problem, came up with the wrong answer. Tried again, didn't get anywhere. Figured there are people here who might be able to show me how to end up with the correct answer.

Way to spam, dumbass. Excuse me, "3L33T3" dumbass.
-- mrcodedude

Oh, I am sorry did I offend you?

I tried to help again, but
nobody was home.

that was pretty lame, but thanks for the effort

Yah well, the last time I took an hour out of my life and did something for this guy he did not even send me a thank you note. So from now on he gets flamed when he asks for free help from his "friends" here at atot.

Link?

BTW, why do your math homework on yellow paper?