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kryton1212
 2 years ago
The graph of y=ax^(2)+bx+c is given as shown. Which of the following is / are true?
I. a<0
II. b<0
III. c<0
A. I only
B. I and II only
C. I and III only
D. II and III only
E. I, II and III
kryton1212
 2 years ago
The graph of y=ax^(2)+bx+c is given as shown. Which of the following is / are true? I. a<0 II. b<0 III. c<0 A. I only B. I and II only C. I and III only D. II and III only E. I, II and III

This Question is Closed

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352549825053:dw

Kira_Yamato
 2 years ago
Best ResponseYou've already chosen the best response.0(C) c < 0 as graph cuts yaxis below the xaxis a < 0 because graph is frowning curve

hashsam1
 2 years ago
Best ResponseYou've already chosen the best response.1E) inverted U shape meaning a<0 intersecting y axis at negative means C is less than 0 c<0 and also there is shift along x axis in right direction means b<0

Kira_Yamato
 2 years ago
Best ResponseYou've already chosen the best response.0Overlooked the detail for b<0... Sorry

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0I am confusing why b>0 is correct

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2the line of symmetry x = b/2a, is a positive value, and we know a < 0 so b > 0

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0I am sorry that I type it wrongly. It should be : "I am confusing why b<0 is correct"

03225186213
 2 years ago
Best ResponseYou've already chosen the best response.0a<0 because parabola opens downward

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0I know a<0 and c<0, I just don't know why b<0 is correct

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2@hashsam1 the line of symmetry is the line x = b/2a. according to the graph it is to the right of the yaxis (so the sign of b/2a is positive). we know that a < 0, so if b < 0 then the sign of b/2a is ()/2() is negative.

phi
 2 years ago
Best ResponseYou've already chosen the best response.0a simple example with 2 positive roots x=1 and x=2 the polynomial would be (x1)(x2) = x^2 +3x 2 this suggests a<0 b>0 c<0

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0I understand now, thank you so much :)

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0another question If f(x)=x(1/x), then f(x)f(1/x)= ?

hashsam1
 2 years ago
Best ResponseYou've already chosen the best response.1oops yes right i over looked the equation thinking its just a normal quadratic equation.

phi
 2 years ago
Best ResponseYou've already chosen the best response.0If f(x)=x(1/x), then f(x)f(1/x)= ? replace f(x) with x 1/x replace f(1/x) with 1/x  x

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352552240065:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352552332194:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352552484497:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0oh .dw:1352552602486:dw

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2you still need to combine x + x

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352552793347:dw

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2i'll accept either form.

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0another question If f(x)=10^(2x), then f(4y)=?

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0A. 10^(4y). B. 10^(2+4y) C. 10^(8y) D. 40^(y) E. 40^(2y)

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2replace x by 4y, what do you get?

nubeer
 2 years ago
Best ResponseYou've already chosen the best response.0f(x)=10^(2x) f(x)=10^(2(4y))

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0If f(x)=x/(1x), then f(1/x)f(x)=?

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352553510302:dw

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2\[\huge f(x) = \frac{ (x) }{ 1(x) }\]

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0If f(x)=x/(1x), then f(1/x)f(x)= f(1/x) = (1/x)/(1(1/x)) = 1/x((x1)/x) f(x) =(x)/(1(x)) = x/(1+x) f(1/x)f(x) = 1/x((x1)/x) times x/(1+x) f(1/x)f(x) = x/(x((x1)/x)(1+x))

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0o.o errrr.... wait a moment

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0f(1/x)f(x) = x/(x((x1)/x)(1+x)) f(1/x)f(x) = x/((x1)(x+1))

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554094668:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554171343:dw

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554144569:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0is it necessary for you to give me a big cross....... I got it :)

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554351232:dw

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554433711:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554512663:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554601402:dw

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554549107:dw

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554682501:dw

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2we're not discussing' we're exchanging notes. hahaha

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554679681:dw

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554776614:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352554942585:dw

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2what's the answer to your problem \[\huge f(\frac{ 1 }{ x })f(x)\]

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0A. 1/2 B. 1 C. (1x)/(1+x) D. x/(1x^(2)) E. x/(x^(2)1) no answer since this is past paper, my teacher haven't give us the answers yet

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0I still cannot get the answer

Callisto
 2 years ago
Best ResponseYou've already chosen the best response.1Please start a new post for a new question. If possible, please also put them in the right categories (subtopics). Thanks!

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2\[\large f(1/x)f(x) = \frac{ 1/x }{ 11/x }\frac{ (x) }{ 1(x) }\] \[\large = \frac{ 1 }{ 1+x \frac{ 1 }{ x }1 } \times \frac{ x }{ x }\]

sirm3d
 2 years ago
Best ResponseYou've already chosen the best response.2just carry out the multiplication and you'll get (D)

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1352556469608:dw I get this only...

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0f(1/x)f(x) = x/(x((x1)/x)(1+x)) f(1/x)f(x) = x/((x1)(x+1)) f(1/x)f(x) = x/(x^2 1) f(1/x)f(x) = x/(x^2 +1) f(1/x)f(x) = x/(1x^2) the answer is D x/(1x^2)

gerryliyana
 2 years ago
Best ResponseYou've already chosen the best response.0you got it @kryton1212 ???? take it a simply way..,hehe

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0confusing................. I think it later another question If a,b and c are all positive, which of the following may represent the graph of ax+by+c=0?dw:1352556954406:dw

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0@hartnn would you kindly help me?

Callisto
 2 years ago
Best ResponseYou've already chosen the best response.1@kryton1212 Please start a new post for a new question!

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0the problem is I cannot draw picture in a new post

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0ok, let this be last question discussed in this post, agreed @kryton1212 ? for this u know how to find intercepts ?

Callisto
 2 years ago
Best ResponseYou've already chosen the best response.1You can post the question a draw it in the comment

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0@hartnn that's ok. c=yintecept

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0nopes, c is y intercept in y=mx+c not here

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0to get x intercept, put y=0 in ax+by+c=0 to get y intercept, put x=0 in ax+by+c=0

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0now tell me what intercepts u get

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0....oh yes. I don't know how to find the intercept in these gaphs

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0to get x intercept, put y=0 to get y intercept, put x=0 in any graphs

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0ax+by+c=0 put y=0??? ax+c=0?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0yes, thats right ax+c=0 x= ?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0absolutely correct! now c/a is positive or negative ?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0given a and c are positive....

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0so your xintercept is negative, that is it will cut x axis in negative (left) side got this ? what about yintercept ???

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0so it may be B or E. y=c/b is it E?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0yes, y intercept is also negative, so it will cut down. and yes its E clear as to how ?

kryton1212
 2 years ago
Best ResponseYou've already chosen the best response.0clear now, thank you

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0make sure u ask next question in new post...

phi
 2 years ago
Best ResponseYou've already chosen the best response.0@kryton1212 it would be better if you made each question a separate post.
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