E Math
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help help...ty ty
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I will only give you hint for this question. You have to try to understand it.Originally posted by Y_Shun:
1) factorise a^2 - b^2 to (a+b)(a-b)
2) Median is centre. So for largest X, the median/centre should lie at the first of the 16 3s. If it's the smallest X, the median/centre will lie on the last of the 16 3s.
Think about it and try again. If still cannot then post again -
Hint again:Originally posted by Y_Shun:
For a normal parabolic curve, the centre of the 2 x-intercepts is the x-value of the min/max of the curve
So you should know the line of symmetry now
Since you hv the x-value, you can find the y value. I believe you forgot to post out the equation of the curve, which is needed in this case.
Now that you hv 2 pts, (0,0) and the max point, you can easily find the equation of the line -
Please post out the full question. Do not post part of a question. A lot of info would have been lostOriginally posted by Y_Shun: -
hmm i post the first left word since they are missing...Originally posted by eagle:Please post out the full question. Do not post part of a question. A lot of info would have been lost
1st line at junction A,
2nd line travels along AC
3rd line while the
4th line Find the -
dun understand leh....Originally posted by eagle:2) Median is centre. So for largest X, the median/centre should lie at the first of the 16 3s. If it's the smallest X, the median/centre will lie on the last of the 16 3s. -
so it shld 1 + 4 = 5Originally posted by eagle:Hint again:
For a normal parabolic curve, the centre of the 2 x-intercepts is the x-value of the min/max of the curve So you should know the line of symmetry now
Since you hv the x-value, you can find the y value. I believe you forgot to post out the equation of the curve, which is needed in this case.
Now that you hv 2 pts, (0,0) and the max point, you can easily find the equation of the line
5/ 2 = 2.5? (but ans sheet = 1.5)
actually i only got prob finding the symmetry, then i shld how to do the latter question. -
They should change the name "10 years series" to "20 years series"
The question for Emaths never change 1 .... -
tht was from some school's exam paper...Originally posted by ispyyy:They should change the name "10 years series" to "20 years series"
The question for Emaths never change 1 .... -
Use the 3 solutions on the curve as the data points for you to sub into the quadratic equation.Originally posted by Y_Shun:so it shld 1 + 4 = 5
5/ 2 = 2.5? (but ans sheet = 1.5)
actually i only got prob finding the symmetry, then i shld how to do the latter question.
Let y=ax2+bx+c,
when y=8, x=0, ==> c= 8
when y=0, x=-1, b=a+8
when y=0, x=4,
thus solving, y=-2x2+6x+8
then dy/dx = -4x+6=0
==> x=6/4 = 1.5 -
latter part, since you got 2 pts for the line,
use m = y1-y2/x1-x2
immediately you get your line equation. Voila! -
oh ya I forgot can get equation from x-interceptsOriginally posted by nightzip:Use the 3 solutions on the curve as the data points for you to sub into the quadratic equation.
Let y=ax2+bx+c,
when y=8, x=0, ==> c= 8
when y=0, x=-1, b=a+8
when y=0, x=4,
thus solving, y=-2x2+6x+8
then dy/dx = -4x+6=0
==> x=6/4 = 1.5
to find the x, all you have to do is
{ (-1) + 4 } / 2 = 3 / 2= 1.5
dy/dx is not required