Math Is Fun Forum
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#1 2014-08-06 23:09:47
- thedarktiger
- Member
- Registered: 2014-01-10
- Posts: 91
Minimum problem
Find all values of p such that 2(x+4)(x-2p) has a minimum value of -18.
Thanks
Good. You can read.
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#2 2014-08-06 23:27:24
- Bob
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- Registered: 2010-06-20
- Posts: 10,621
Re: Minimum problem
hi thedarktiger
If the quadratic is of the form y = ..... then it will have a vertical line of symmetry. ie. straight through the minimum point.
Here's an example:
As you know the minimum y, and one of the roots, you should be able to form some equations to get the other.
Such as: Let the minimum point be at (q,18).
Then q must fit the equation and q is equidistant from -4 and 2p.
Bob
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob 
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#3 2014-08-06 23:42:26
Re: Minimum problem
That red-blue graphing tool looks familiar. what is it?
'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.
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#4 2014-08-07 00:24:03
- Bob
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- Registered: 2010-06-20
- Posts: 10,621
Re: Minimum problem
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob
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#5 2014-08-07 01:34:31
Re: Minimum problem
Thanks
'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.
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