chhote chhote limits....

Q1. lim(x→2a) [√x-2a + √x - √2a]/[√x2-4a2]

Q2. lim(x→∞)2x(√x2+1 - x)

85 Answers

1
spiderman ·

in first question do the square brackets mean greatest integer function????
second question ka answer 1 tha i was writing working galti se del ho gaya ....

second wala main rationalise and we get

2x(x2 + 1 - x2 ) /√x2 +1 +x

ab divide by x
and we get 2 / 2 bus yeh dhyaan rakhna hai ki x2 approaches infinity then 1/ x2 is zero jab tum root main divide karogay ...

1
pavanmalhra ·

U CAN ALWAYS APPLY L'HOSPITAL 80% QUESTIONS GET EASILY SOLVED BY THIS METHOD

106
Asish Mahapatra ·

obviously doubts hain....

39
Dr.House ·

same question

106
Asish Mahapatra ·

Q4.. lim(x→0)lxl[cosx] where [.] is GINT.
i know this is of the form... (→0)(→0)

but is that 1... i know us par ek QOD bhi tha jo abhi classics mein bhi hai...

is it bcz.

lny = lim(x→0)[cosx]lnlxl
lny = 0 [as [cosx] = 0]
so, y = e0 = 1

106
Asish Mahapatra ·

106
Asish Mahapatra ·

11
Mani Pal Singh ·

Q7 mein
limx-->0 (1+x)1/x=e(1+x-1)/x =e (standard result)

now the ques answer is not defined or limit does not exist

106
Asish Mahapatra ·

bhaiya what is d/dx((1+x)1/x)?

and Q5. the ans. is coming 3/2 but its given 3/4....

62
Lokesh Verma ·

Q6.

\lim_{x\rightarrow 0}\frac{e-(1+x)^{1/x}}{x} =\lim_{x\rightarrow 0}\frac{d/dx(e-(1+x)^{1/x})}{dx/dx} =\lim_{x\rightarrow 0}\frac{d/dx((1+x)^{1/x})}{1}

does this help?

62
Lokesh Verma ·

\frac{sec4x-sec2x}{sec3x-secx} =\frac{1/cos4x-1/cos2x}{1/cos3x-1/cosx} =\frac{cos2x-cos4x}{cosx-cos3x}\times\frac{cos3x\times cosx}{cos4x \times cos2x}
Now, I think you need to only use COS A + COS B in numerator and denominator

106
Asish Mahapatra ·

Q5. lim(x→0)(sec4x-sec2x)/(sec3x-secx)
i know this ones easy but i cant solve it... isme to l'hospital bhi use nahiin ho sakta....

Q6. lim(x→0) [e-(1+x)1/x]/x .... [.] is NOT GINT. its juist square brackets....

Q7. lim(x→0)[(1+x)1/x -e + (ex/2)]/x2

106
Asish Mahapatra ·

chodo silly doubt very silly.... thread open to new questions but closed for Q4. [3]

106
Asish Mahapatra ·

ya phir is it the simple reason...
for x→0,
RHL = l0.0000001l0exact = 1
LHL = l-0.0000001l0exact = 1

???

62
Lokesh Verma ·

e-∞ = 1?

62
Lokesh Verma ·

are these doubts or for other guys?

1
Akand ·

ya dude asish.........perfect.........

106
Asish Mahapatra ·

Q1. lim(x→2a) [√x-2a + √x - √2a]/[√x2-4a2]

when x→2a+ then √x-2a is defined.... but when x→2a- then √x-2a is not defined... so will limit exist?? i dont think so......

1
skygirl ·

[1]

106
Asish Mahapatra ·

thanks sky and manipal...

1
spiderman ·

sandwich ke alawa aur bhi tareeka hai ...........
split gint into fractional part and x
x= [x] + {x}
and then split and solve

1
skygirl ·

q.3)

limit exists.

let,

y= lt x->0 |x|sinx

ln y = lt x->0 sinx ln|x|

=> ln y = lt x->0 (sinx/ x) (ln|1+(x-1)|/ (x-1)) . x(x-1) =0

=> y=1

1
skygirl ·

q.3)

limit exists.

let,

y= lt x->0 |x|sinx

ln y = lt x->0 sinx ln|x|

=> ln y = lt x->0 (sinx/ x) (ln|1+(x-1)|/ (x-1)) . x(x-1) =0

=> y=1 ans.

11
Mani Pal Singh ·

no asish q3 is correct and the answer is one
first understand that u cant do it directly
take log

it becomes
logy=sinx logx
now
logy=logx/1/sinx (∞/∞form use l hospital)
now differentiate to get the answer[1]

106
Asish Mahapatra ·

Q3. ans given 1....
sky Q1. bhi solve kar do naa..

Your Answer

Close [X]