Ver
@pooja195 i really need help
\[\frac{ \tan(x)+\pi }{ 2 }=-\cot(x)\]
please write out how to verify this one please
thinking about it.
i think the question is \[\tan(x) + \frac{\pi}{2} = -\cot(x)\] am i right ?
ah yea, that would make sense. then you could use cofunction identities I believe
or \[\tan(x+ \frac{\pi}{2})=-\cot(x)\]
yes thats correct @Nnesha
yup yup, trying to figure it out now
i hope you know that tanx = sinx/cosx \[\tan(x+\frac{\pi}{2})= \frac{\sin(x+\frac{\pi}{2})}{\cos(x+\frac{\pi}{2})}\]now you can apply sum/difference formula which is \[\large\rm \sin(x+y)= sin(x) cos(y)+\cos( x) \sin( y)\]\[\rm \cos(x+y)=\cos(x)\cos(y)-\sin(x)\sin(y)\]
That should work.
@Nnesha got it?
so @Nnesha proved it?
yes.apply sum formula ive posted above
thank you so much. @Nnesha
yw. let me know what you get. i can check your work
if you have any question..feel free to ask
I don't know how to apply it when I try... :-(
@Loser66
Can you post the original question by scanning?
Question: verify the identity: tan(x+π2)=−cot(x)
ok
\(\color{blue}{\text{Originally Posted by}}\) @Nnesha or \[\tan(x+ \frac{\pi}{2})=-\cot(x)\] \(\color{blue}{\text{End of Quote}}\)
oops I meant: tan(x+π/2)=−cot(x)
\(tan(x +\pi/2)=\dfrac{sin(x+\pi/2}{cos(x+\pi/2)}\) OK?
ok
Now, numerator: \(sin(x+pi/2)= sin xcos(\pi/2)+sin(\pi/2) cos x\) OK?
oh ok! got it so far.
but cos (pi/2) =0 and sin(pi/2)=1, so numerator = cos x OK?
ok
Now, denominator \(cos(x+\pi/2) = cos x cos(\pi/2) - sinxsin(\pi/2)\) again , \(cos(\pi/2) =0, sin(\pi/2) =1\) hence denominator = -sin x, ok?
ok
numerator/denominator = cos x/-sin x = -cot x that's it
ah ok. So that proved it all? I see now. Can you check one of my other proofs for me?
ok
thaks! Here it is:
1.) Verify the identity. quantity one minus sine of x divided by cosine of x equals cosine of x divided by quantity one plus sine of x -1 - sin x / cos x = cos x / 1 + sin x , then 1 - sin x / cos x X 1 + sin x / 1 + sin x then, 1 - sin^2 x/cos x (1 + sin x) , cos^2 x / cos x (1 + sin x), and then cos x / 1 + sin x.
So I listed the question and then the answer
math notation, please
one minus sine of x, but you wrote -1-sin(x) ???
the question was: Verify the identity: 1-sinx/cos x = cos x/ 1+sin x. I wrote: 1 - sin x / cos x = cos x / 1 + sin x , then 1 - sin x / cos x X 1 + sin x / 1 + sin x then, 1 - sin^2 x/cos x (1 + sin x) , cos^2 x / cos x (1 + sin x), and then cos x / 1 + sin x.
this is the trick!! You have to go from the left hand side to the right hand side, right? the denominator of the right hand side is (1+sinx) how to get it from the left hand side? just multiple both numerator and denominator of the left hand side by it!!
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