C1 and C2 DOUBTS HERE!!!!!

[~ Miss Relina ~]

Sure =]

In the Question it stated the words "Real root" , and when you see that then you should know that you should undoubtedly use " > or greater than or equal" .

How did I know that , look into these notes I posted prior


EDIT: Regarding your doubt about Sketching Graphs ,I found some notes that could help.

Attached.

Source of the Notes : http://getrevising.co.uk/resources/c1_sketching_curves

well okay the notes say the same thing I say too
in both questions which you had solved before the question said real roots which should be greater than or equal but you used less than or equal
that's my point dear 

[The Golden Girl =D]

well okay the notes say the same thing I say too
in both questions which you had solved before the question said real roots which should be greater than or equal but you used less than or equal
that's my point dear 

At first I used Greater than or Equal but then I used less than an equal.

Clarification :

a=k, b=8, c=5
x={ - b plus or minus (square root ?b2?4ac) }/2a

b2-4ac greater than or equal  0 for real roots. So
82-4k * 5 greater than or equal 0
64-20k greater than or equal 0
64 less than or equal 20k
64 /20 less than or equal k
k less than or equal  3.2

The on in RED and BOLD. Why I changed it into less than becase if you noticed we moved the 20 K to the RIGHT side of the inequality and you should know whenever you MOVE the unkown *one with X or K example : 20 K* you CHANGE the Sign

I hope you got my point

[~ Miss Relina ~]

At first I used Greater than or Equal but then I used less than an equal.

Clarification :

The on in RED and BOLD. Why I changed it into less than becase if you noticed we moved the 20 K to the RIGHT side of the inequality and you should know whenever you MOVE the unkown *one with X or K example : 20 K* you CHANGE the Sign

I hope you got my point

oh ralyy I've never heard about that ''whenever you MOVE the unkown *one with X or K example : 20 K* you CHANGE the Sign ''
what I know is that when we just divide or multioly an inquality we change signs only
anyways thanks
but what about the first two questions in my first post Q 3 E [4 a and b] they mentioned real roots but you used less than or equal to get the answer right
by the way I know your method is right ofcourse because you git the right answer but  i am just confused sorry of the conflict between the two examples 3E-4a and 3 F-9

Thanks for all your efforts I have made you tired I think

[The Golden Girl =D]

oh ralyy I've never heard about that ''whenever you MOVE the unkown *one with X or K example : 20 K* you CHANGE the Sign ''
what I know is that when we just divide or multioly an inquality we change signs only
anyways thanks
but what about the first two questions in my first post Q 3 E [4 a and b] they mentioned real roots but you used less than or equal to get the answer right
by the way I know your method is right ofcourse because you git the right answer but  i am just confused sorry of the conflict between the two examples 3E-4a and 3 F-9

Thanks for all your efforts I have made you tired I think

You seem to be REALLY confused. Habeebti ,I'll explain everything inshAllah ....It's Alright I'm free for now so I am not tired =]

Okay I'm going to Quote what I said and Color it in RED so that you see that there is no need to get confused AT ALL

(a) a=1, b=-k, c=k+3
b2-4ac<0 for no real roots, so
k2-4(k+3)<0
k2-4k?12<0
(k-6)(k+2)<0
-2<k<6

(b) a=p, b=p, c=-2
b2-4ac<0 for no real roots, so
p2+8p<0
p(p+8)<0
-8<p<0

This is NO real roots which is why it is <  

a=k, b=8, c=5
x={ - b plus or minus (square root ?b²?4ac) }/2a

b2-4ac greater than or equal  0 for real roots. So
82-4k * 5 greater than or equal 0
64-20k greater than or equal 0
64 less than or equal 20k
64 /20 less than or equal k
k less than or equal  3.2

This is Real roots which is why it is greater than or equal  

I hope you got my point =]

Don't forget to include me in Your Prayers =D

[~ Miss Relina ~]

@G.G : Thanks alot
well anyone knows any information about How to find the vertical and horizontal asymptotes of the reciprocal 1/x  

[The Golden Girl =D]

You're welcome .. don't forget to include me in your prayers

I didn't get your request , can you elaborate please ?

[~ Miss Relina ~]

You're welcome .. don't forget to include me in your prayers

I didn't get your request , can you elaborate please ?

never mind I searched and got it Allhamduliallah

[The Golden Girl =D]

I'm glad you did =] ..I'm here if you need my help though

[~ Miss Relina ~]

well if anyone have C2 and  you can help then here is my question page 66 exercise 4D question 3 :
my problem is that i  donot know how to ge the r²  however Iwas able to get the centre point right I found in the back of the book answers but I was totally confused and don't know the exact method

ahhhh.....By the way you don't need to do  the whole  exercise  just one example would be fine

Thanks in advance 

[Malak]

Okay sorry for the previous reply

Here is what you do.

When a quadratic equation is given use completing the square to find the center and radius and then find the equation of circle.

See this for the best explanation
http://www.examsolutions.co.uk/maths-revision/core-maths/coordinate-geometry/circle/centre-radius/tutorial-1.php

[~ Miss Relina ~]

Okay sorry for the previous reply

Here is what you do.

When a quadratic equation is given use completing the square to find the center and radius and then find the equation of circle.

See this for the best explanation
http://www.examsolutions.co.uk/maths-revision/core-maths/coordinate-geometry/circle/centre-radius/tutorial-1.php

well thanks for the link I'll check it
 but now you made me curious   about ur previous reply as I didn't see it ......I'm going to accept it as long as u are helping me thank you very much   hope Allah help you with anything you want  

[~ Miss Relina ~]

well after checking the link I found it too useful but the problem is why this rule apply to the book equations I 'll show you one :
x² + y² + 4x + 9y +3 = 0
my answer is :
(x+2)²-4 + (y + 4.5 )² -20.25 +3 = 0 then adding the numbers will give -13.25 so the equation will be :
(x+2)² + (y+ 4.5 )² = 13.25
so centre point should be ( -2 ,-4.5 ) and radius=  square root 13.25  
right ??
  why the book did it like that :
(x+2)² + (y + 3 )² -10= 0
(x+2)² + (y + 3 )² = 10
so centre point is ( -2,-3) and radius=square root10




well.............the answer to the question shouldn't be like that unless there is a mistake and instead of 9y it should  be 6y

plz guys try it and tell me as I found all the other examples like that  

[Arthur Bon Zavi]

well.............the answer to the question shouldn't be like that unless there is a mistake and instead of 9y it should  be 6y

Yes, it should be 6y and not 9y.

[~ Miss Relina ~]

Yes, it should be 6y and not 9y.

thanks a lot for your respond can you check others too 

I've attached questions and book answers  and first one done  but others not can u plz check them too
sorry for disturbing 

[Arthur Bon Zavi]

thanks a lot for your respond can you check others too  

I've attached questions and book answers  and first one done  but others not can u plz check them too
sorry for disturbing  

You can do the rest by applying the same equation of the circle.