Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#2 Re: Help Me ! » Limits n->infinity questions on factorials » 2013-02-01 02:07:26

^^just edited my earlier post. It is for the first one.

#3 Re: Help Me ! » Limits n->infinity questions on factorials » 2013-02-01 02:04:14

Wow! A lot of discussions on hmms.. in this post.
Now, the answer in the book says that the answer for question (1) is 1/2.
Is it right or there is a printing mistake?

#4 Help Me ! » Limits n->infinity questions on factorials » 2013-01-30 03:56:56

mttal24
Replies: 24

I am trying to solve questions like:

1.


and
2.

How do I solve them?
for the first one, i get upto lim 1/n+2. Then what should I do?

#5 Re: Help Me ! » Geometric sequence » 2013-01-30 03:51:26

Well, to identify and prove a geometric progression the following can be used:
If
t2/t1=t3/t2=t4/t3=.....=tn/t(n-1)=r  (and 'r' also represents common ratio)
then the sequence is a GP.
Here,
1/2^4 divided by1/2 is equal to 1/2^7 divided by 1/2^4.
Thus, you can show that it is a gp

#6 Help Me ! » Trignometric functions and ratios for any angle » 2012-06-15 17:55:51

mttal24
Replies: 1

I have read all basics of trignometry and  I have a question:
Find 

and

I have read all the questions related to these on mathsisfun.com but all the questions there are like sin 330 is given and a related acute angle's value is given.
But how do I convert this into an acute angle?

#7 Re: Help Me ! » Proofs » 2012-06-15 17:49:08

Are you asking about proof by Mathematical Induction?

#9 Re: Help Me ! » Relations and Functions: Domain and range of special functions » 2012-06-01 16:41:12

benice wrote:

(1)
Notice that [x] ≤ x < [x]+1 for all x∈ R.
x ∈ R-Z
=> 0 < x-[x] < 1
=> 1/(x-[x]) > 1
=> f(x) = 1/sqrt(x-[x]) = sqrt(1/(x-[x])) > 1

Thanks. But what do you mean when you say that since x∈R-Z so the equation 0<x-[x]<1.

And thanks very much for the second question. I realised what I was doing wrong.

#10 Re: Help Me ! » Relations and Functions: Domain and range of special functions » 2012-05-30 17:25:52

^^Thanks.
I have done it as you said.
x-[x] ≤0
=> x≤[x]
That is only possible when x is an element of Z(Integers)
=> Domain is (R-Z) [R is the set of real nos. and Z is that of integers].

Now for Range, what should I do?

#11 Help Me ! » Relations and Functions: Domain and range of special functions » 2012-05-29 21:56:06

mttal24
Replies: 6

I have been able to find the domain and ranges of questions but this one is not coming:

(1)


By [x] here, I mean Floor function or greatest integer function.

Also,
(2) This modulus function question, I am not able to understand how to get values for the conditions:

If f(x) be defined on

and is given by
  f(x) = {-1 for -2≤x≤0 and (x-1) for 0<x≤2 }

and g(x) = f(|x|) + |f(x)|. Find g(x). Here | | means Modulus.

#12 Re: Help Me ! » Trignometry: Question on a Trignometric equation » 2012-05-13 20:15:30

Thanks.
Lets say, I begin answering by:


Now, I know sec/cos is negative between
implies,

But, here we are taught by a different method where we see that the main identities that,

Similarly,

I tried understanding this in many books, which I wrote as

And, in some books I see that, suddenly out of the blues, a person adds

to
and makes it

Now, I have understood that after reading the same question for the past 5 days.
But your method seems to be faster.

#13 Re: Help Me ! » Trignometry: Question on a Trignometric equation » 2012-05-13 16:44:09

Thanks
And if

then how would you do since a -ve value means

#14 Help Me ! » Trignometry: Question on a Trignometric equation » 2012-05-12 23:47:00

mttal24
Replies: 5

I know that a principal solution of a trignometric equation is 2 values lying between


But I don't know how to find them.
Lets take a question,
Find the principal solutions of

I know,

And, in some books I see that, suddenly out of the blues, a person adds
to
and makes it

I just know that values of sine and cos repeat after

Please give me full explanation on how to find this. Please explain with one more example so that it becomes clear to me :

#15 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-09 21:00:06

That means that the fx is undefined for denominator=0 because anything/0=undefined

#16 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-09 18:04:13

One last thing please,
Can you explain how to solve
|x-2|/x-2 ≥ 0
My ans is:x ≥2
But book's ans is: x>2

#17 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-09 17:08:07

Thanks. Finally I understood something...

#18 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-08 20:23:08

^^Thanks.
In the book, the answer given is
soln. set of the inequation is (-infinity,-2) union (-1/2, +infinity).
But, you have given x<2 which would mean (-infinity, 2)

#19 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-08 16:50:51

@bob bundy
I have two for you:

1. |x-1|/x+2<1

2. |x-1|+|x-2| ≥4

#20 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-07 21:13:56

^^ thanks. But how to do a little faster without a graph? I am seeing books which use zeroes of the linear equations given in numerator and denominator enclosed in the mods and then proceed.

#21 Re: Help Me ! » Linear Inequalities/Inequations Question » 2012-05-07 19:33:53

Thanks...
One thing more,
Can you show me a detailed procedure on how to solve inequations with the moduluses like | x-1 |

#22 Help Me ! » Linear Inequalities/Inequations Question » 2012-05-06 22:15:29

mttal24
Replies: 20

My question,

   
------------------------------------------------------------------------------------------------------
I understood that, all terms have to go on LHS, to solve in form:

1. But how to proceed ahead? Please explain me step-by-step.
------------------------------------------------------------------------------------------------------
2. When you reach the end, you get two values(here, fractions), say c and d. Then how do you decide whether:


or

Similarly,

or

#23 Help Me ! » Set Theory: Proof » 2012-05-03 20:32:01

mttal24
Replies: 1

Q. Show that for any sets A and B, A = (A ∩ B) ∪ (A – B).

Please show me by the method of "let x∈A..."

Board footer

Powered by FluxBB