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secondary 4 | E Maths
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Date Posted: 4 years ago
Views: 206
y = 0.057x - 0.001x²
dy/dx = 0.057 - 2(0.001)x
= 0.057 - 0.002x
Maximum for such a quadratic function is when dy/dx = 0
0.057 - 0.002x = 0
0.057 = 0.002x
x = 0.057 ÷ 0.002
x = 28.5
The splenic artery resistance is a maximum at 28.5 weeks (the 29th week)
dy/dx = 0.057 - 2(0.001)x
= 0.057 - 0.002x
Maximum for such a quadratic function is when dy/dx = 0
0.057 - 0.002x = 0
0.057 = 0.002x
x = 0.057 ÷ 0.002
x = 28.5
The splenic artery resistance is a maximum at 28.5 weeks (the 29th week)
Alternative :
For a quadratic curve with the formula y = ax² + bx + c ,
dy/dx = 2ax + b
when dy/dx = 0,
2ax = -b
x = -b/2a
here your a = -0.001 and b = 0.057
x = -0.057/2(-0.001)
= 0.057/0.002
= 28.5
For a quadratic curve with the formula y = ax² + bx + c ,
dy/dx = 2ax + b
when dy/dx = 0,
2ax = -b
x = -b/2a
here your a = -0.001 and b = 0.057
x = -0.057/2(-0.001)
= 0.057/0.002
= 28.5
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