3D geo

If the straight lines
x-1/k=y-2/2=z-3/3 and x-2/3=y-3/k=z-1/2
intersect at a point then k is equal to

(a)5
(b)2
(c)-2
(d)-5

31 Answers

1
Mirka ·

but if u solved d other way, that is, equate both to A & B and eliminate A nd B to get K,
u also get a (2-k) in d denominator.

1
Mirka ·

@ R.I.P :
i think d first row of ur det shud hav been k 3 3
nd not k 2 3 as u hav done

11
Mani Pal Singh ·

bhai wohi to likha hai

examine carefully!!!!!!!!!

11
Subash ·

But how do you get this determinant??

Wasnt the det supposed to be what i have written in #17

11
Mani Pal Singh ·

@ ani
this is done now

we have to take the determinant

|k 2 3 |
|3 k 2 |=0
|1 1 -2|

solving this we get k=-5 or k=5/2

so answer is D

11
Anirudh Narayanan ·

arey, someone.....atleast point out the mistake in my solution

11
Mani Pal Singh ·

@ ani
I am sorry 4 the inconvenience

the option A is 5

now the question is PERFECT and the answer is FROM THE OPTIONS GIVEN

11
Anirudh Narayanan ·

RIPper, have a look at ur options, a and d are the same!!!(-5)

Maybe, option d was meant to be -5.5......

1
Honey Arora ·

wtz the ans given?
it cld be 'd' which is around the ans

11
Anirudh Narayanan ·

here's my solution

PLS POINT OUT THE MISTAKE (IF THERE IS ANY)!!!!

11
Anirudh Narayanan ·

I solvd two times and both times, i got -11/2 ....same as asish....... RIPper, i think one of the options must be -11/2.......maybe u have posted the options for the next question....[3]

1
°ღ•๓яυΠ·

11
Mani Pal Singh ·

can any body help[17]

11
Subash ·

that is tamil word for dude

1
Mirka ·


Machan
??

1
Pavithra Ramamoorthy ·

machan.......... theres somethin else we ve to do.. or flaw in d question...

go n sleep.... u ll get everythin in mind...

;-)

1
Pavithra Ramamoorthy ·

put
x-1/k=y-2/3=z-3/3=\lambda

x-2/3=y-3/k=z-1/2=\mu

equate any two variables in terms of\lambda& \mu

then solve it..

11
Subash ·

here is something more direct if two lines intersect

lx2-x1 y2-y1 z2-z1l
l l1 m1 n1 l
l l2 m2 n2 l

the above determinant =0

(k-3)(2k+11)=0

But both roots are not in the options [2]

106
Asish Mahapatra ·

i took let x-1/k=y-2/3=z-3/3 = s
So, x=sk+1, y=3s+2 and z=3s+3

Put them in x-2/3=y-3/k=z-1/2

u get sk-1/3 = 3s-1/k = 3s+2/2
if u equate 1 and 2,
then s=(k-3)/(k2-9) .. (i)
equate 1 and 3, u get
s=8/(2k-9) .. (ii)
Solving these two...
u get k=-11/2 and k=3 (this doesnt satisfy (i))

1
Mirka ·

oh!

but 3 is not in option

1
Pavithra Ramamoorthy ·

hey.. loser.. i said i ve to leave now..

n wat i get is

(\lambda +\mu)(3-k)=0

doin in very urgency.. ignore if wron..

btw, loser tell ur name.. its not soundin gud to call u loser..

106
Asish Mahapatra ·

@mirka .. k=3 will be elimintated bcz in sum pt. of my calculations k-3 was coming in the denom...

1
Mirka ·

yeah it'll take time ...

but u get d same thing ...

i mean, i can't make d same silly mistake twice !

106
Asish Mahapatra ·

im getting k=-11/2 ??

1
Pavithra Ramamoorthy ·

pls wait... hmmm.. its gettin time fr me...

1
Mirka ·

REALLY ??

but i checked it twice !
wat is it tht u r getting ? u get (2 - k) in denom ryt?

anyway, wats d answer 2 dis Q ??

1
Pavithra Ramamoorthy ·

hey loser.. u don get dis by simplifyin.. i think u made a mistake somewhere..

pls do check it again..

1
Mirka ·

On simplifying !!

11
Mani Pal Singh ·

how did u get this[7][7][7]

1
Mirka ·

solving by above method, u get this,

so, wat cud be d answer?

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