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denis_g

Member

Registered: 2015-04-05

Posts: 1

Algebra 2: Quadratics

Find all values of p such that
2(x+4)(x-2p)
has a minimum value of -18.

Please explain your answer as thoroughly as possible, as I am very much stuck

Last edited by denis_g (2015-04-05 03:08:27)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Algebra 2: Quadratics

Hi;

Easiest is to use the properties of a parabola ( ax^2+bx+c=0 ) which says the vertex is located at

Expand out your problem.

Equate coefficients.

a = 2

b = ( 8 - 4p )

c = - 16 p

The coordinates are

We set the y coordinate to -18 and solve for p.

p = 1 or p = - 5

Draw the graph to convince yourself that you have indeed found a minimum.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
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Olinguito

Member

Registered: 2014-08-12

Posts: 649

Re: Algebra 2: Quadratics

Now find all p such that this is equal to the given minimum value.

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