Questions

1) Evaluate limx->infinity cosx/x or explain why it doesnt exist?

2) Evaluate lim t->4 (t-√3t+4)/t-4 or explain why it doesnt exist?

3) Evaluate lim x->13 x-1/√x-1 or explain why it doesnt exist?

4) Let f(x)= sinx/x if x#0

f(x)= 1/2 if x=0

Discuss the continuity of f(x) and Sketch.........

Plz Give the Answers

58 Answers

11
Mani Pal Singh ·

SANKAR put 1/x =t now the ques becomes limx>infinity sint/t
so the answer is 0

33
Abhishek Priyam ·

where its wrong...

definition of limit:

as x approaches a certain quantity... (always keeping itself in the domain of the function....) then if f(x) approaches a certain fixed quantity.. then that quantity approached by f(x) is called limit of function.

3
msp ·

sry abhi for talking hindi dat much badly.

3
msp ·

but cos(∞) is not approaching a particular quantity

11
Mani Pal Singh ·

the concept is
ANY NUMBER DIVIDED BY INFINITY IS ZERO

3
msp ·

then wat is the no in this case

11
Mani Pal Singh ·

REMEMBER THAT COS X LIES BETWEEN -1 TO 1
THERE SHOULD BE NO CONFUSION

33
Abhishek Priyam ·

@shankara...

but cos(x)/x approaches a fixed quantity... zero...

1
Harry Potter ·

hey priyam congrats yaar.........

3
msp ·

then i can give u a limit can u find this for me.

limx→0(sin(1/x)/1/x)=

33
Abhishek Priyam ·

we should talk tommorow on this topic...

today i think my mind is sleeping for an hour...

Byee talk to u all tommorow... [1]

1
skygirl ·

priyam i think... x/x^2 undefined for x->0. [12]

1
Philip Calvert ·

@ sankara answer to ur que ∞

3
msp ·

priyam the graph also gives ur explanation.

3
msp ·

yes philip u r rite can u pls explain.

in this qn also wont sin(∞)=undefined

3
msp ·

sky cos(∞)=k how

11
Mani Pal Singh ·

REMEMBER THAT COS X AS WELL AS SINX LIES BETWEEN -1 TO 1
THERE SHOULD BE NO CONFUSION

3
msp ·

mani ur rong da. philip is rite.

33
Abhishek Priyam ·

sorry.. i had to go to sleep.. i forgot that... talk to u all, later

1
Philip Calvert ·

no maybe i am wrong even now i think it should have been 0 idont know why i wrote inf there [7] sorry but i really think answer is 0

3
msp ·

kk abi have a gud sleep.

11
Mani Pal Singh ·

priyam ur ques is diff as limx>0 sinx could be written as x
but not in ur case

11
Mani Pal Singh ·

clear me if u think i am wrong

3
msp ·

if u have some confusion may be the defn of limits can help u.

if it is not helping then draw a graph using a software

11
Mani Pal Singh ·

which software????

3
msp ·

microsoft math 3.0 as abi suggested

11
Mani Pal Singh ·

can u give me the link??

33
Abhishek Priyam ·

@shankara...

Lim xsin(1/x) =0
x→0

Lim cos(x) =0
x→0 x

apply sandwitch theorem to both..

39
Dr.House ·

hey guys use expansion of sinx and cosx and answer is at your feet.

33
Abhishek Priyam ·

differentiate karo na..

lim 1 - 3
t→4 2√3t+4

=1-3/8
=5/8

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