3 Unit Maths Question (Trigonometry) (1 Viewer)

[DSar]

Prove the following identity:

Step-by-step please
Thanks

 

[elbatiolpxeho]

There is no such identity, the thingymabob isn't true for all values of x.

Also, why doesn't the Year 11 forum allow embedded images? Cunt.

 

[Drongoski]

ohex

U r right. To be an identity it must hold for all values of the argument theta. But if we just choose a convenient theta = pi/3 say, we can easily show LHS not equal to RHS.

 

[laplace10]

lool noobs I think there is a typo

if you change it to (sinx)^2 (tanx)^2 +2sin(x)cos(x) + (cotx)^2 (cosx)^2

then you get LHS = [ sin(x)tan(x) +cot(x)cos(x)] ^2

you prob get somewhere from that

 

[SpiralFlex]

I think it's just a not in the LHS. Assuming the previous statement is true,

 

[laplace11]

LOL the OP was a massive noob, can even write the question correctly

 

[DSar]

I think it's just a not in the LHS. Assuming the previous statement is true,

Thanks a ton. Appreciate it. I'm guessing you used the 2 Unit Fitzpatrick book?

LOL the OP was a massive noob, can even write the question correctly

"Sue me, Dickhead."- Arnold Swarchenegger

 

[SpiralFlex]

Thanks a ton. Appreciate it. I'm guessing you used the 2 Unit Fitzpatrick book?

No. I use 3 unit Cambridge, Fitzpatrick and in the process of Terry Lee Fundamentals.

 

[greenboxes]

Wait, how did you get from the second line to the third line? My trig test is tomorrow, FML >_<

 

[SpiralFlex]

Wait, how did you get from the second line to the third line?

Not to fear. I assume you mean,



TO



All I did was expand the brackets.

 

[RANK 1]

wtf dude as if u didnt get that, u really need to study more

 

[greenboxes]

I really do, cause I still don't get it...

 

[SpiralFlex]

All part of the learning process.

 

[RANK 1]

go to mathsonline.com and look at their videos most of them are really simple examples but they still help

 

[RANK 1]

shame they dont have ext 2

 

[greenboxes]

I feel really dumb but the sharpie I'm working this out with is starting to smell funny, so... could you please explain how you changed 1-cos squared theta into negative sin theta cos theta...?

 

[RANK 1]

because he expanded it and multiplied 1 with sin theta/cos theta then multiplied cos^2 theta with sin theta/cos theta and the cos theta canceled out giving sin theta cos theta

 

[SpiralFlex]

I feel really dumb but the sharpie I'm working this out with is starting to smell funny, so... could you please explain how you changed 1-cos squared theta into negative sin theta cos theta...?

You are not "dumb". We are not expected to get things straight away.



Remember we times 1 and times



=

 

[RANK 1]

how do you write the mathematics, do i need a program or is it built into windows

 

[greenboxes]

Oh wait I get it thanks!