I did so many hard questions and I can't finish off the last question! Please help with the last bits below:
N = -8 + 13d – 2d square 2
When N = 0 then -8 + 13d – 2d square 2 = -8
Rearranging gives:
2d² – 13d + 8 = -8
Solving gives:
d = ? =?
Solving 2d² – 13d + 8 = -8?
2008-10-24 10:24 am
回答 (5)
2008-10-24 12:06 pm
✔ 最佳答案
2d^2 - 13d + 8 = -82d^2 - 13d + 8 + 8 = 0
2d^2 - 13d + 16 = 0
d = [-b ±√(b^2 - 4ac)]/2a
a = 2
b = -13
c = 16
d = [13 ±√(169 - 128)]/4
d = [13 ±√41]/4
∴ d = [13 ±√41]/4
2008-10-24 5:45 pm
2d² – 13d + 8 = -8 add 8 to both sides
2d² - 13d + 16 = 0
Quadratic Formula
{ -(-13)± â[(-13)² - 4(2)(16)] } / 2(2)
[13 ± â(169-128)] / 4
d = [13 ± â41] / 4
I haven't done algebra in months, but I am confident in my answer.
2d² - 13d + 16 = 0
Quadratic Formula
{ -(-13)± â[(-13)² - 4(2)(16)] } / 2(2)
[13 ± â(169-128)] / 4
d = [13 ± â41] / 4
I haven't done algebra in months, but I am confident in my answer.
2008-10-24 5:31 pm
After rearranging gives
2d² – 13d + 8 = 8 not -8
2d² – 13d=0
d(2d-13)=0
d=0 or d=13/12
or
d=[-b+sqrt(b^2-4ac)]/2a or d=[-b-sqrt(b^2-4ac)]/2a
here a=2, b=13,c=0
Subtitute these values in formula
2d² – 13d + 8 = 8 not -8
2d² – 13d=0
d(2d-13)=0
d=0 or d=13/12
or
d=[-b+sqrt(b^2-4ac)]/2a or d=[-b-sqrt(b^2-4ac)]/2a
here a=2, b=13,c=0
Subtitute these values in formula
2008-10-24 5:28 pm
2d² - 13d + 16 = 0
d = [ 13 ± â (169 - 128) ] / 4
d = [ 13 ± â (41) ] / 4 gives exact answers.
d = [ 13 ± â (169 - 128) ] / 4
d = [ 13 ± â (41) ] / 4 gives exact answers.
2008-10-24 5:31 pm
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