Help with math problem

[Gober]

Okay I am not gonna lie, it is a homework problem I need help with. I know it is against the forum rules to ask for help but it's just a single problem. So I ask the mods may I please post this problem?

Okay onto the problem. I have to prove.

1+Tan(t)Tan(2t)=Tan(2t)Cot(t)-1

[This name sucks]

Okay I am not gonna lie, it is a homework problem I need help with. I know it is against the forum rules to ask for help but it's just a single problem. So I ask the mods may I please post this problem?

Okay onto the problem. I have to prove.

1+TantTan2t=TantCott-1

What kind of problem is that, exactly?

It looks like some kind of trig with finding tangents.

[Gober]

What kind of problem is that, exactly?

It looks like some kind of trig with finding tangents.

Yes it is trig. I have to prove both sides are the same. So I gotta make one side look exactly like the other using trig identities and algebra. The thing is you can only work one side you have to leave the other alone.

[Deleted]

Ah, Math, my old nemesis, we meet again.

[Fuzzzie]

Okay I am not gonna lie, it is a homework problem I need help with. I know it is against the forum rules to ask for help but it's just a single problem. So I ask the mods may I please post this problem?

Asking for the solution to your homework is not allowed. Asking to be pushed in the right direction is fine. What specifically are you having a problem with here?

[Garnier Fructis]

Your textbook should have a list of trig identities. Take a look at those and try a few out to see if you get anywhere.

[Deleted]

Do you happen to have the list of trig proofs? Like the basic SOH, CAH, TOA stuff. In order to prove that one equals the other I'm fairly sure you'll need to use them

[Gober]

Asking for the solution to your homework is not allowed. Asking to be pushed in the right direction is fine. What specifically are you having a problem with here?

I don't exactly want the solution because it is already in the problem, I want the steps on how to get there. I spent like an hour just trying different identities and so far none have worked out =/

[Fuzzzie]

I don't exactly want the solution because it is already in the problem, I want the steps on how to get there. I spent like an hour just trying different identities and so far none have worked out =/

I understand. I wish I could help more. I haven't done Trig in almost 15 years and googling a few things hasn't helped jog my memory much. Best of luck!

[Gober]

Your textbook should have a list of trig identities. Take a look at those and try a few out to see if you get anywhere.

Here's a list of all the identities I can use. http://www.sosmath.com/trig/Trig5/trig5/trig5.html

[Deleted]

Here's a list of all the identities I can use. http://www.gnaa.eu/browser/trollforg...es.gif?rev=476

Out comes the pen & paper. Been a few years but I'll see what I can come up with

[Gober]

Out comes the pen & paper. Been a few years but I'll see what I can come up with

I changed the link. This one is a little simpler I believe.

[MerinPally]

I'm writing it out now in an attempt to work it out but think of it this way.

Look at the right hand side of the equation.

tan x * cot x

= (sin x / cos x) * (cos x / sin x) = 1

Then you have -1 so the right hand side of the equation is equal to 0, so you have to prove that ( 1 + tan x tan 2x) = 0

[Nutshell]

Hi. Can you double check the identity, please? I think there is a mistake somewhere.

Yep, the guy above me is right.

[Blueobelisk]

I'm writing it out now in an attempt to work it out but think of it this way.

Look at the right hand side of the equation.

tan x * cot x

= (sin x / cos x) * (cos x / sin x) = 1

Then you have -1 so the right hand side of the equation is equal to 0, so you have to prove that ( 1 + tan x tan 2x) = 0

I thought the right side was tan(t)cot(t-1) not tan(t)cot(t) - 1

OP can you clarify? Is the -1 part of the cotangent term or on it's own?

[gazaway]

cot(t) * tan(t) = 1 . That should be a good place for you to start. Remember that tan(t) = sin(t)/cos(t) and cot(t) = cos(t)/sin(t) . Then use the conversions that you have to simplify the rest. It's actually a fairly easy problem just asking you to use substitutions from that url you posted.

[Gober]

I'm writing it out now in an attempt to work it out but think of it this way.

Look at the right hand side of the equation.

tan x * cot x

= (sin x / cos x) * (cos x / sin x) = 1

Then you have -1 so the right hand side of the equation is equal to 0, so you have to prove that ( 1 + tan x tan 2x) = 0

Poop I am sorry I copied the problem down wrong. It was supposes to be tan2xcotx-1 on the right side.

[Blueobelisk]

Oh by the way I also need to ask if you can manipulate both sides, because usually in a proof you can only touch one side. Which would cause a problem in MerinPally's answer.

[Deleted]

Hi. Can you double check the identity, please? I think there is a mistake somewhere.

Yep, the guy above me is right.

Yeah I think there might be a mistake myself. Having touble equating the two.

[Gober]

Hi. Can you double check the identity, please? I think there is a mistake somewhere.

Yep, the guy above me is right.

Yes there was a mistake I fixed it though it is correct now.