limits

PLEASE SOLVE THIS 1

38 Answers

11
virang1 Jhaveri ·

This limit is making me tend towards madness

1
Manas ·

u cannot explain these limits questions as better as u can do.
everyone has his/her own methods of doin it.

1
Manas ·

then i dont hav any idea

1
Manas ·

hey can u try by L-Hospital's rule

11
Anirudh Narayanan ·

11
Mani Pal Singh ·

sahi pakda boss

ab tu bata de
isse kaise karein[17]

11
Mani Pal Singh ·

koi to isse kar do

yy is this thread neglected[2]

62
Lokesh Verma ·

try taylor series expansion!

1
Optimus Prime ·

1-32

11
Mani Pal Singh ·

sir kar ke bata do na

meko taylor series nahin aat[2]

11
Mani Pal Singh ·

THE ANSWER IS 2/9
I HOPE THIS WOULD HELP

1
Akand ·

wat r u doin manas??

i think this is lhospital....

L=lim 2x-3√x3+x2+1-3√x3-x2+1
1/x2

now use lhosiptal......

11
Mani Pal Singh ·

dude please solve till u get the result [1]

1
archana anand ·

divide & multiply wid x den it wud b ∞/∞ form den apply L'hospital guess dats gonna help

11
Mani Pal Singh ·

akand ne yehi kia hai
uss se phas rahe hain[2]

62
Lokesh Verma ·

Using binomial expansion for fractional powers....

(1+1/x+1/x^3)^{1/3} =1+\frac{1}{3}(1/x+1/x^3)+\frac{\frac{1}{3}(\frac{1}{3}-1)}{1.2}(1/x+1/x^3)^2 + \text{higher order terms}

(1-1/x+1/x^3)^{1/3} =1+\frac{1}{3}(-1/x+1/x^3)+\frac{\frac{1}{3}(\frac{1}{3}-1)}{1.2}(-1/x+1/x^3)^2 + \text{higher order terms}

Now you can add the two and get

(1-1/x+1/x^3)^{1/3} + (1-1/x+1/x^3)^{1/3} =2+\frac{2}{3}(1/x^3)-2/9x^2+\text{higher order}

66
kaymant ·

First, set y=1/x, so that the required limit becomes
\lim_{y\to 0} \dfrac{2-\sqrt[3]{y^3+y+1}-\sqrt[3]{y^3-y+1}}{y^2}
Since y→0, therefore y3+y+1≈1+y and y3-y+1≈1-y. So the above limit becomes
\lim_{y\to 0} \dfrac{2-\sqrt[3]{1+y}-\sqrt[3]{1-y}}{y^2}
Apply the binomial expansions
\sqrt[3]{1+y}=1+\dfrac{y}{3}-\dfrac{1}{9}y^2+\dfrac{10}{3^3}y^3+\ldots + terms containing y4 and higher powers.
and
\sqrt[3]{1-y}=1-\dfrac{y}{3}-\dfrac{1}{9}y^2-\dfrac{10}{3^3}y^3-\ldots-terms containing y4 and higher powers.
Therefore,
2-31+y-31-y=2y2/9 + terms containing y4 and higher powers.
So when we divide by y2, we get the required ratio as
2/9 + terms containing y2 and higher powers of y.
Hence when y→0, we get the required limit as 2/9.

62
Lokesh Verma ·

The original question now becomes

\lim_{x\rightarrow \infty} x^2\times(-\frac{2}{3}(1/x^3)+2/9x^2+\text{higher order})

Thus it becomes

\lim_{x\rightarrow \infty} (2/9-\frac{2}{3}(1/x)+\text{higher order})

= 2/9

62
Lokesh Verma ·

oh kaymant sir you were doing this one already :)

1
Manas ·

yah but ultimately when u get 0 other things dont matter

11
Mani Pal Singh ·

na ji na
keep trying

1
Manas ·

hey divide the whole equation by x2 and then take the remaining x inside the cube root then it will become x3.

then u can divide the eqn under the root and then u can put x=infinity and then u get

2-1-1=0 is the ans

11
Mani Pal Singh ·

ALARM

WARNING : MANAS U R IN GR8 TROUBLE

DUDE HOW CAN U DIVIDE AN EQUATION BY x WHEN x TENDS TO INFINTY ????

1
Manas ·

then wats the ans for the question

1
Manas ·

hey u can .
u do the things in that way only

1
Manas ·

u divide by x2 and not x

11
Mani Pal Singh ·

bhai the mistake u r committing is the following

IN MATHEMATICS
U CAN NEVER DIVIDE AN EQUATION WITH A NUMBER 0 OR ∞ AS IT MAKES NO SENSE[1]

62
Lokesh Verma ·

manas you can divide but dont you think you have to mulitply it back?

1
Manas ·


see the ans and tell me whether i m wrong

1
ANKIT GOYAL ·

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