Maths Prelim Question (1 Viewer)

Varin9

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Hi, can someone please post the working out for this question, because for some reason myne is like 3 pages long lol, x^2 - 5x + a, find the value of a
 

Varin9

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回复: Re: Maths Prelim Question

well it says, a has exactly one root, its a quad ratic
 
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Using the completing the square method
a=(-5/2)^2=25/4
you really should use the determinate method ( as it is more likely a prelim student will understand your soln )

so for exactly one root the determinate must equal zero

and there determinate= b^2 -4ac = (-5)^2 -4 ( 1)(a) = 25 -4a

we set equal to zero and get a= 25/4
 

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