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#326 Re: Help Me ! » hi, any help with these two question? » 2016-12-22 12:31:28

Hannibal lecter

these I'm while I'm trying to solve it myself :

like I said I stuck because of x^s and I stuck because of number 2 in the second question...

1482452951651.jpg

#327 Help Me ! » hi, any help with these two question? » 2016-12-22 12:03:45

Hannibal lecter
Replies: 27

hello
I tried to solve these two question about absolute value inequality but I stuck with x^2 and with number 2

please see this picture and solve this two for me,  the answer of my teacher for 1) is (-∞,1] U [9,∞)

and for 2) is (-∞,∞)

is it right?


I tried the a way that a member learned me that here but I stuck

solve this in short way for me please!!! it takes me 3 days and I didn't find any solution :

1482451359491.jpg[URL="http://www.up-0

#328 Re: Help Me ! » about Absolute Value.... » 2016-12-20 09:11:04

Hannibal lecter
zetafunc wrote:

can't be a solution, because
while

and what is that mean if I mean from where did you get |-1+3| there is just |x-3| and |x+1| in the expression I don't see |x+3|?
and do you mean it can't be equal to -1 because when we replace -1 by |x-3| ≤ |x+1| it will be |-1-3| ≤ |-1+1| then |-4| ≤ |0| and that is false it can't be -1, ... is that right? is I'm doing a good step or not....

zetafunc wrote:

So now you know that the values for which your inequality hold are:

and

The intersection of these sets is
. That is, the result of combining the above two inequalities is

To summarise, the left-hand side of what your lecturer wrote is fine. For the rest, see the above.


you said inequality are hold x > -1
and x ≥ 1.

so where is number zero?  why the inequality sol is not [0,∞) ?

#329 Re: Help Me ! » about Absolute Value.... » 2016-12-20 07:28:29

Hannibal lecter
Mathegocart wrote:

Sometimes it is more intuitive to explain it in the alternate form, which is also applicable for absolute values.
And yes, heed zetafunc's warning, sometimes it can introduce extraneous solutions.

may you please solve it like my lecturer did but in simple way without these strange number lines and +++ or ---

if you have a free time please, I need you sol with your elegant words and short steps. with greater and smaller and with interval notations.

#330 Re: Help Me ! » about Absolute Value.... » 2016-12-20 07:13:59

Hannibal lecter
zetafunc wrote:

The important part to take away from your lecturer's solution is that
is equivalent to

but mathegocart didn't do like the lecturer did, what does it changed? how the solution is

,

and the sol of the teacher is :

,
U {-1}.



zetafunc wrote:

it's important in general to go back and check whether or not the solutions you've found are actually valid.

but how to do that? I mean how to check wether or not the solution is valid or not????
how did you know the solution was fine please help with that...

#331 Re: Help Me ! » about Absolute Value.... » 2016-12-20 05:55:33

Hannibal lecter

Believe me if there is another way to help myself with, I'm sure I'll follow this way, but this is the only place that I can get help with a specific questions in math.
thank you very much.

so....is this the end of the solution? but how did you do that with an absolute value? ((( I mean we must take two possibilities once in >=0 and once in < 0 )))))???

please see this following picture, is the the solution of our lecturer in the university :- what is this? I really hop you to help me with full details about that


1482256157981.jpg




I always asking him about problems but our lecturer don't show respect to who ask him about that he learning us he just writing these problems without careful and caring sad ...

#332 Re: Help Me ! » about Absolute Value.... » 2016-12-19 08:36:50

Hannibal lecter

thank you for this great example,

can I ask you another question it was difficult to me to solve it :-

<=

or like this

<= 1

please may I get the full solution for this? with its interval notation

#333 Re: Help Me ! » LaTeX - A Crash Course » 2016-12-19 07:42:12

Hannibal lecter

thanks,,, and maybe I need to put a root inside this fraction

what can I write

#334 Re: Help Me ! » LaTeX - A Crash Course » 2016-12-19 00:42:25

Hannibal lecter

how to write the number line? and how to write the numerator and denominator fractional and how to put a variables inside the absolute value? I mean inside bars | | | | ?

#335 Re: Help Me ! » about Absolute Value.... » 2016-12-17 12:15:42

Hannibal lecter

thank you very much Mathegocart

can I ask another question?

what is that mean :

1482020053631.png


what i u ?
and why +-a

#336 Re: Help Me ! » about Absolute Value.... » 2016-12-16 22:53:46

Hannibal lecter

thank you bobbym,


and #zetafunc sorry but I don't understand these symbols you provided, I'm not like you I just do simple mathematics I don't even know what is


and I wish to know what is these beautifull symbols
sorry

#337 Re: Help Me ! » about Absolute Value.... » 2016-12-16 22:50:06

Hannibal lecter

#Mathegocart

yes thank you very much I got it now.

but can we say the abs -6 is -6 too? cause it is just a sign. what will happen if we say that

#338 Introductions » Hi, » 2016-12-16 22:36:02

Hannibal lecter
Replies: 2

Hello, .... I'm zaid and nice to meet you all


I just feel that I'm very annoying here and don't make people feel happy

because I ask too much then usual ( that because of my bad past in mathematics). so if anyone feel that I'm disturbed just tell me and I'll leave the forums.
or if anyone from this point that have an advice for me, please go ahead and tell me.


Greeting

#339 Help Me ! » about Absolute Value.... » 2016-12-16 15:51:10

Hannibal lecter
Replies: 23

Hi,

I study the absolute value maybe more than 2 times in my life,, when I was in the school and now and on the internet for myself

now I read (Absolute Value  how far a number is from zero) .. then it is mean abs for 6 is 6 and -6 is 6

what is the meaning of that? and if it was about how far the number 6 from zero is the meaning of abs
then why -6 is 6 ? why the abs -6 is -6?



I apologize for such questions again and again.. I don't have another way to understand! sorry

#340 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-16 15:45:39

Hannibal lecter

thank you very much ...

#341 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-16 15:34:04

Hannibal lecter

no I didn't, I just say that as example, cause we have this topic in our syllabus and our lecturer didn't notice us about anything whatever..

#342 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-16 08:15:15

Hannibal lecter

another question please .. do you see this picture below :

1481919220841.png





is that mean I can't write a solution for this inequality? or I can write sol : either x > 3 or x < 3 ?
I mean when y teacher ask me to write an answer what should I write? there is no answer or the answer is : either x > 3 or x < 3?


Greeting

#343 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-16 07:45:32

Hannibal lecter

10 + 10 = 20 , x >= 10
is that right?

#344 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-15 22:30:28

Hannibal lecter

but as well as please see what I did

the question tell What is x+3, when we know that x is greater than 11??

my way to sol : x+3 >> 11 +3 = 14  then we get x > 14

another question in  my mind (for example ) ... What is x+4, when we know that x is greater than 16??

my sol : 16 + 4 = 20  then x > 20


is that right? please tell me

and can you give me a similar example let us use >= ( greater or equal) ?

thank you.

#345 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-15 22:18:26

Hannibal lecter

thank you very much now I understand what you write,

I also like to know it in very more accurately and maybe I'll do that in the future

#346 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-15 11:23:08

Hannibal lecter

thank you very much,

can we start in my first question? back to this Example above

when he told me : (Imagine that "x" is the number of people at your party.......)

I tried to read it more than one times but I didn't understand it.

when I imagined it I understand there is 14 in my party but how we can say (If x > 11 , then x+3 > 14) in that easy!!!!!!

I mean when I imagined it I just have the power to write ( x+3 > 11 ) hehehe cause I imagined there is 11 and just added 3 it became like this
I don't have the power to write the right mathematical formula which is (If x > 11 , then x+3 > 14) ,,


heeeeeeeeeeeeeeeeeeeeeelp me in that please

#347 Re: Help Me ! » about something called "discrete mathematics" » 2016-12-10 09:43:39

Hannibal lecter

Hi, I didn't understand what you said, can you explain your words please, I'll try to play these games later but I need to study discrete mathematics like (if and only if)

I did it in university with our techer but I need to study it from math is fun.com

#bobbym

he told us there is a relationship between discrete mathematics and computer science,

so can you help me find any website or link in math is fun.com

1481406361821.jpg

#348 Help Me ! » about something called "discrete mathematics" » 2016-12-10 00:34:11

Hannibal lecter
Replies: 5

Hi,
I'm asking about discrete mathematics, we take this course in our studies but I didn't saw it in math is fun.com

it is about if p then q and if and only if.... and it is about True or False,...etc

can anyone tell me where can I find an introduction about discrete mathematics in math is fun?

#349 Re: Help Me ! » question about an example I saw at math is fun » 2016-12-09 21:58:01

Hannibal lecter

thank you bobbym and bob bundy and I'll read it,

#bobbym

of course I can solve inequalities but that because I used to solve it but not understanding the meaning of it 30% because I don't have (a past knowledge in algebra)  so I decided what you told me that " I'll solve inequalities for now and after that I'll come back for more algebra after I have a time for that"
is that a good plan?

thank you very much

cause in these days in university the student need to understanding what is going on not just doing it without a knowledge about what he is doing cause I don't study math only, I study a topics in computers that have a relative in maths. like programming and some engineering topics

thank you very much for your help see you soon

#350 Help Me ! » question about an example I saw at math is fun » 2016-12-09 10:34:18

Hannibal lecter
Replies: 17

Hi, while I'm study Inequalities I see this example :-

1481883084691.png

he said before the example ("OK, this example may be complicated if you don't know Algebra, but I thought you might like to see it anyway:")

is that mean I have to study and read all Algebra Topics?

I read and study this :-

Introduction to Algebra
Balance when Adding and Subtracting (animation)
Introduction to Algebra - Multiplication
Order of Operations - BODMAS, or PEMDAS
Substitution
Equations and Formulas
Inequalities and Solving Inequalities
definitions Basic Algebra Definitions
...

do I have to continue study the rest of topics like :

Exponents
What is an Exponent?
Negative Exponents
Reciprocal in Algebra
Square Roots, Cube Roots, and nth Roots
Surds
Simplifying Square Roots
Fractional Exponents
Laws of Exponents
Using Exponents in Algebra
Multiply and Divide Variables with Exponents
Simplifying
Expanding (removing parentheses)
Multiplying Negatives
Associative, Commutative and Distributive Laws
Cross Multiply
Directly Proportional and Inversely Proportional
Fractions in Algebra
Factoring
Factoring - Introduction
Logarithms
What Is A Logarithm
Logarithms Can Have Decimals
Working with Exponents and Logarithms


Polynomials
What is a Polynomial?
Adding And Subtracting Polynomials
Multiplying Polynomials
Polynomial Long Multiplication
Rational Expressions
Dividing Polynomials
Polynomial Long Division
Conjugate
Rationalizing The Denominator
Special Binomial Products
Linear Equations
Equation of a Straight Line
Explore the Straight Line Graph
Cartesian Coordinates
Quadratic Equations
Quadratic Equations
Quadratic Equation Solver
Factoring Quadratics
Completing the Square
Solving Word Questions
Solving Word Questions
Solving Inequality Word Questions
Functions
Definition of a Function
Sequences and Series
Sequences and Series
Sequences - Finding a Rule
.
.
.
.
.
.
.
.
.
. then to Algebra 2 and collage algebra!




because my teacher in the university told me to study Inequalities and Solving Inequalities just that!

so can I study it and without study the rest of algebra?

please tell me what I need to study before I study Inequalities


Greeting

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