Thursday, July 5, 2007

Find the mistakes.






Hi everyone,





I need you to find the mistakes of this solution given by a student. You just need to describe
i) where is the mistake
ii) what is the correct solution.
Lastly,
iii) what is the difficulty that you find in this chapter?

Remember to sign off your name.






31 comments:

shafeeq said...
This comment has been removed by the author.
shafeeq said...

How To Answer????

If anyone finds out please let me know ASAP.... email me but dont msn my mobile....or sms me PLEASE & THANK YOU

Anonymous said...

-[(x-7/2) =-93/4
i am not sure...

Anonymous said...

dunno lu.

Anonymous said...

i) behind never minus (7/2)^2

ii) -maximun turning point
- x-intercept = 0.184 or -5.158
- y-intercept = 6.816
- mid-point = -2.487

iii) Very easy to make calculations mistake during the steps.

answer wrong, i dont know. cause most likely is wrong. :D

Anonymous said...

dun understand lu.. ahhaha

Anonymous said...

dunno where is the mistake ...
dunno know therefore i dunno wad's the correct solution ...

i feel that the difficulty in this topic is that i dun know how to do completing square !

~aLiCiA

Anonymous said...

i duno the mistake how i noe the correct solution.haha.the difficult thing is the completing the square. very lecey.

-nadiiiiahhhh

Anonymous said...

i)-1 times -93/4=93/4

ii)max tp(7/2,93/4)

when x=0,y=-[(0-7/2)^2-93/4]
so -(49/4)+93/4
=-11

when y=0,(x-7/2)^2+93/4=0
(x-7/2)^2=-93/4
because there has no root of -93/4
so it cannot solve it

iii)NA

Anonymous said...

1)*the second step of y-intercept:
-[49/4-93/4]≠49/4-93/4
*the second step of x-intercept:
-(x-7/2)^2+93/4=0≠-(x-7/2)^2=93/4

2)max t.p. =〉(7/2,93/4)

y-intrcept => x=0,
∴y=-[(0-7/2)^2-93/4]
=-[49/4-93/4]
=11

x-intercept => y=0,
∴-[(x-7/2)^2-93/4]=0
(x-7/2)^2=93/4
(x-7/2)=√93/4
x-7/2=4.82 or x-7/2=-4.82
x=8.32 0r x=-1.32

3)nil

Anonymous said...

1)*the second step of y-intercept:
-[49/4-93/4]≠49/4-93/4
*the second step of x-intercept:
-(x-7/2)^2+93/4=0≠-(x-7/2)^2=93/4

2)max t.p. =〉(7/2,93/4)

y-intrcept => x=0,
∴y=-[(0-7/2)^2-93/4]
=-[49/4-93/4]
=11

x-intercept => y=0,
∴-[(x-7/2)^2-93/4]=0
(x-7/2)^2=93/4
(x-7/2)=√93/4
x-7/2=4.82 or x-7/2=-4.82
x=8.32 0r x=-1.32

Anonymous said...

1)*the second step of y-intercept:
-[49/4-93/4]≠49/4-93/4
*the second step of x-intercept:
-(x-7/2)^2+93/4=0≠-(x-7/2)^2=93/4

2)max t.p. =〉(7/2,93/4)

y-intrcept => x=0,
∴y=-[(0-7/2)^2-93/4]
=-[49/4-93/4]
=11

x-intercept => y=0,
∴-[(x-7/2)^2-93/4]=0
(x-7/2)^2=93/4
(x-7/2)=√93/4
x-7/2=4.82 or x-7/2=-4.82
x=8.32 0r x=-1.32

Anonymous said...

1)*the second step of y-intercept:
-[49/4-93/4]≠49/4-93/4
*the second step of x-intercept:
-(x-7/2)^2+93/4=0≠-(x-7/2)^2=93/4

2)max t.p. =〉(7/2,93/4)

y-intrcept => x=0,
∴y=-[(0-7/2)^2-93/4]
=-[49/4-93/4]
=11

x-intercept => y=0,
∴-[(x-7/2)^2-93/4]=0
(x-7/2)^2=93/4
(x-7/2)=√93/4
x-7/2=4.82 or x-7/2=-4.82
x=8.32 0r x=-1.32

Anonymous said...

i)-the second step of y-intercept
-the second step of x-intercept
-the max turning point

ii) y= -[(x-7/2)^2-93/4]

the max t.p => ( 7/2, 93/4)
y-intrcept => x=0
∴ y= -[(0-7/2)^2-93/4]
=-(49/4 - 93/4)
=11

x-intercept => y=0,
∴ -[(x-7/2)^2-93/4]=0
-(x-7/2)^2 + 93//4 =0
-(x-7/2)^2 = -93/4
(x-7/2)^2 = 93/4
x = 7/2+√93/4, 7/2-√93/4
= 8.32 , -1.32

i think is the completing square method

Anonymous said...

i dunno =)

Anonymous said...

dunno leh

Anonymous said...

i dun noe how 2 explain ..

jun yan

Anonymous said...

~the second line
max point is not (7/2,-93/4)
is (7/2,93/4)
~correction of y-intercept
is y=-[(0-7/2)^2-93/4]
=-[49/4-93/4]
=11

Anonymous said...

i do not understand the working. Can anyone tell me what is wrong

Yvonne

Anonymous said...

i dunno how to do completing squares...

Anonymous said...

i dun't know =))

Anonymous said...

i dunno =DD

Anonymous said...

second step of y-intercept second step of x-intercept the max t.p

y= -[(x-7/2)^2-93/4]

the max t.p => ( 7/2, 93/4)
y-intrcept => x=0
∴ y= -[(0-7/2)^2-93/4]
=-(49/4 - 93/4)
=11

x-intercept => y=0,
∴ -[(x-7/2)^2-93/4]=0
-(x-7/2)^2 + 93//4 =0
-(x-7/2)^2 = -93/4
(x-7/2)^2 = 93/4
x = 7/2+√93/4, 7/2-√93/4
= 8.32 , -1.32

Anonymous said...

the second step of y-intercept
the second step of x-intercept
the max turning point

i dun know to do it...

Anonymous said...

i dunno....

dunno therefore no answer


difficult to draw graph.....

fiona said...

i)turnin point,y and x intercept are wrong


ii)max t.p (7/2 , 93/4)
y-intercept is suppose to be
-49/4 + 93/4= 11
x-intercept is suppose to be
-(x-7/2)^2= -93/4
(x-7/2)^2= 93/4
x-7/2= +/-root 93/4
x= root 93/4+7/2 &
-root 93/4+7/2
i tink lol

iii)difficulty in completing spuare?? i dunno lol XD

Anonymous said...

i dunno...

Azleen

Anonymous said...

max t.p => 7/2, 93/4
y-intercept =-[(0-7/2)^2-(93/4)]=-(49/4-93/4)=-11

Found it diffcult to completing the sq method.


~~Junkai

Anonymous said...

Sry answer is 11.

Junkai

Anonymous said...

how to do?
dont even know!

Anonymous said...

M.X point will be
(7/2 , 93/4 )
Vic