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Grade 12th PassDifferential Calculus

Find the range of [1/sin{x}]

[.] denotes GIF, {.} denotes fractional part.

Profile image of Speed Racer
14 Years agoGrade 12th Pass
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3 Answers

Profile image of Chetan Mandayam Nayakar
ApprovedApproved Tutor Answer14 Years ago

Dear Speed,

f(x)=[1/sin{x}],0≤{x}<1,

0≤sin{x}<sin(1 radian)

1/(sin(1 radian))<1/sin{x}<∞

f(x) is any integer greater than [1/sin(1 radian)]

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CHETAN MANDAYAM NAYAKAR

Profile image of Ashwin Muralidharan IIT Madras
ApprovedApproved Tutor Answer14 Years ago

Hi Speed Racer,

 

Clearly 0≤{x}<1.

So 0≤sin{x}<sin1

Now 1<pie/2, but 1>pie/6.

So sin1<1. but sin1>1/2

 

So sin{x} can take all values from (0,1/2+delta]...... (where delta is >0)

 

And hence the range of this function would be all positive integers.

As sin{x} can be = 1/n where n=2,3,4,...... (also sin{x} = 1/2+delta, would give 1/sin{x} lies between 1 to 2)

So [1/sin{x}] = 1.

 

And hence range is all positive integers.

 

Hope that helps.

 

All the best.

Regards,

Ashwin (IIT Madras).

Profile image of Shraddha sharma
7 Years ago
I'm a 12th class student....I'm not good in functions...but .. According to me....  Sin{x} can never be zero...
So. Sin( x- [x] )  also never be zero.... Zero can be written as sin(0) ... Therefore  x-[x] not equal to zero...so x should not be equal to [x]... And that's only possible in integral points.... But as I have recommended this site I came to know that its ans. Is  all +ve integers.... And even after going through the solution... I'm not getting the reason that why my way is wrong??? Can anyone please explain this to me????