Question of the week 10-Dec-2017
If (Tan 2θ - Tan θ)/ (1 + Tan 2θ * Tan θ) = 1, then the
possible value of θ is
a) 45 b) 225 c) Both d) None of the above
a) 45 b) 225 c) Both d) None of the above
Answer to the previous week question here. Current question is a trap question. Don't expect that i would give simple question. I expect that most would answer it incorrect and it is very much a CGL level question. This question is part of my upcoming book and it is solvable in less than 10 seconds. Your answer only with a logical explanation is welcomed in the comments section.
Solution (25-Dec-17):
If you haven't already solved this question, i request you to try this question first and then read further.
It is two weeks since i asked this question and not even one person was able to answer this question correct. Many might have thought that the answer is either 45 (option a) or both (option c). If anyone is good at formulas, he would have said it is 45 and a person who has more command over Trigonometry, he would have said Tan 225 = Tan 45 = 1 after applying ASTC tip. When i said it is a trap question, people might have been more cautious and inclined to mark Option C instead of Option A. All such people are wrong and that it not the actual trap.
Actual answer is Option D. Did you think where have you been wrong? Both the options (45, 225) will make the expressions given in the question to infinity/infinity which can never be '1'. Recall your school learning that our answer should always satisfy the given question when cross verified. If you are not satisfied with my explanation, you may approach any IIT tutor as he is the right person to correct your basics.
Stay tuned for more questions and related tips. I making sure that my upcoming book is with such beautiful problems reading which will provoke your thoughts and bring out the outstanding person in you.
Solution (25-Dec-17):
If you haven't already solved this question, i request you to try this question first and then read further.
It is two weeks since i asked this question and not even one person was able to answer this question correct. Many might have thought that the answer is either 45 (option a) or both (option c). If anyone is good at formulas, he would have said it is 45 and a person who has more command over Trigonometry, he would have said Tan 225 = Tan 45 = 1 after applying ASTC tip. When i said it is a trap question, people might have been more cautious and inclined to mark Option C instead of Option A. All such people are wrong and that it not the actual trap.
Actual answer is Option D. Did you think where have you been wrong? Both the options (45, 225) will make the expressions given in the question to infinity/infinity which can never be '1'. Recall your school learning that our answer should always satisfy the given question when cross verified. If you are not satisfied with my explanation, you may approach any IIT tutor as he is the right person to correct your basics.
Stay tuned for more questions and related tips. I making sure that my upcoming book is with such beautiful problems reading which will provoke your thoughts and bring out the outstanding person in you.
(Tan2x -Tanx)/(1+Tan2x.Tanx)= Tan(2x-x)=Tanx= 1 so value of theta here is 45°
ReplyDeletehi. what are the post retirement career options for a CBI officer? People in IT , CBEC work as consultants , auditors and so on. what about CBI officers?
ReplyDeleteAnswered in new article. Pls check
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ReplyDeleteAlready answered in other article of this blog. Pls check
DeleteTan x= 1
ReplyDeleteX=45
Tan (225')=tan (180+45)
By ASTC=tan 45 both true