1.

{:(,"List-I",,"List-II",),((P),"The number of integral values of k for which the ",(1),1,),(,"equation" sin^(01)x^(-2)+tan^(-1)x^(2)k+1 "has a solution",,,),((Q),"Let" sum_(K=1)^(oo)cot^(-1)(k^(2)/(8))=(p)/(q)pi where" (p)/(q) "is rational in its lowest",(2),2,),(,"form then find" |q-p|,,,),((R),"If" tan^(-1)(sin^(2)theta-2 sin theta +3)+cot^(-1) (5^(sec^(2)_(y)+1)=(pi)/(2), then the",(3),3,),(,"value of" cos^(2)y-sin theta,,,),((S),"Minimum positive integral value of x such that f(x)",(4),0,),(,"is defined" f(x)=sqrt(sec^(-1)((1-|x|)/(2))),(4),0,):}

Answer»

`{:(P,Q,R,S),(3,1,2,2):}`
`{:(P,Q,R,S),(4,3,1,4):}`
`{:(P,Q,R,S),(1,3,2,3):}`
`{:(P,Q,R,S),(1,4,3,2):}`

Solution :Let `f(x) =sin^(-1)x^(2)+TAN^(-1)x^(2)`is `UARR` even
function and domain is `[-1.1]`
`f(x)|._(min) =f(0)=0`
`f(x)|_(min) =f(1) =(pi)/(2)+(pi)/(4)=(3pi)/(4)`
`f(x)in[0.(3pi)/(4)]`
`if K=0,2k+1=1`, possible
if `k=1, 2k +1=3gt(3pi)/(4)` Not possible
i.e only one integral value of k is possible
(Q) `T_(K)tan^(-1)((8)/(k^(2)))=tan^(-1),(2)/(k^(2)/(4))=tan^(-1),(2)/(1+((k)/(2)-1)((k)/(2)+1))`
`T_(K)=tan^(-1)((k)/(2)+1)-tan^(-1)((k)/(2)-1)`
`T_(1)=tan^(7).(3)/(2)-tan^(-1)((-1)/(2))`
`T_(2)=tan^(-1).(4)/(2)-tan^(-1)0`
`T_(3)=tan^(-1).(5)/(2)-tan^(-1).(1)/(2)`
`T_(4)=tan^(-1).(6)/(2)-tan_(-1),(2)/(2)`
`T_(5)=tan^(-1).(7)/(2)-tan^(-1).(3)/(2)`
:
:
`Sum =`
`2pi-(-tan^(-1).(1)/(2)+tan_(-1)/(2)+tan^(-1)1)=(7pi)/(4)impliesp=7,q=4`
`(2pi us sum of last four term)`
we know `tan^(-1)x + cot^(-1) y=(pi)/(2)impliesx=y`
according to question
`underset([2.6])ubrace((sintheta-1)^(2)+2)=underset(ge6)ubrace(5sec^(2)y+1)`
Only possible `implies sintheta -1 =-1`
`sin theta=-1`
` sec^(2)y=1implies cos^(2)y=1`
`cos^(2)y-sin theta=2`
`(S) sec^(-1)( (1-|x|)/(2))ge0implies (1-|x|)/(2)ge1`
or `(1-|x|)/(2)le-1`
`1|x|ge2 or 3le|x|`
`-1ge|x|0r x epsilon (-oo,-3]uu[3,oo)`
Not possible
least positve integer is 3


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