1ok, i got it
cos-1(x2-1 / x2+1) + 1/2 * tan-1(2x/1-x2) = 2Ï€/3.
Solve for x
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28 Answers
1yes prajith.....
"hey Philip
cos-1(cos(-2θ)=cos-1(cos(π-2θ).........dont u remember........"
toh maine kya log 10 likha hai iski jagah[11]
that pi - 2θ did not drop from the heavens
11pata nahin
i
didnt
saw ur
solution
and its different 4m ur ways(i hope )
11here it is
i made a small mistake
and now corrected it!!!!!!!!!!!!!
1@manipal. but wat abt using cos-1.....Where is the mistake in our method...
1Its my mistake...Philip u r rite....( but my max sir hav specifically rounded the answer with red ink and wrote as wrong one)
1hmm..... oK Thanks guys 4 ur efforts!!...I shud hav asked my teacher regarding this one one that day itself....The probability of this type of question in Inverse trigs is very very less(hoping)..Bye :-) ALL THE BEST 4 UR MAX xams..
1see raghav .......maybe u got it wrong bcos of you wrong treatment of
cos-1(-x)
1no philip i was just reminding u of that thing....thts all.i was hw our procedure can be wrong.........
1put x= tan θ
u'll get
cos-1(-cos2θ) + θ = 2π/3
π - 2θ + θ = 2π/3
θ = π/3
x = √3
i hope it is correct...
though i have to admit i may have made some mistakes cuz didnt use pen and paper
1hey Philip
cos-1(cos(-2θ)=cos-1(cos(π-2θ).........dont u remember........
1are u sure answer is not root 3 and the question is perfectly correct......
bcos most times this way we shud get the answer.....
i think that tan term in my solution has a mistake but cos-1 is perfectly correct........
___________________
1yes i have a feeling that root 3 might be wrong.. i am still trying
1matrix pls read question carefully
its x sq -1 not 1- x sq in cos inverse term
1then after applying x=tanθ
cos-1(-(1-tan2θ)/(1+tan2θ))+tan-12tanθ/(1+tan2θ)
=cos-1(-cos2θ)+tan-1(tan2θ)
........ Rest is urs........now.........
11bhai a better idea
cos-1x ko tan-1x ki form mein likh le and apply the formula
u will get the answer
if any troubles then ask again
i will tell
now i am taking dinner
1wat root 3 is wrong .....[7]
then i have missed something ... ok lets see [12]
1K philip.I did the same in my exam. my problem is cos-1(x2-1/x2+1)... I wrote cos(-θ) = cos(θ).. and got it as √3...But the answer is wrong... It is our pre board question.....Someone rectify if it is wrong...