Math Is Fun Forum

Slowlrnr

Member

Registered: 2010-01-26

Posts: 14

I need a shove in the right direction

I have become stuck in varies areas in solving the following problems. If you can help then I can see what/where I am having problems. Sorry but my parents are no help.

Determine the coordinates of the vertex for the graphs of the following function.

F(x)= 2x^2-10x+14

I calculated the H to be 2 1/2 using -b/2a

When I plugged H into the formula I got 6.12?

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Given f(x)=2x^2-x-3, determine the coordinates of the vertex and interceps. Sketch the graph.

I calculated  X= -1 or X=1 1/2
H= 1/4
k= i got stuck

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Find the value(s) of X that satisfy each of the following inequalities. Express your solution in interval notation.

3x^2+5x >_ 2  ( the >_ is greater than not equal to )

I calculated x=1/3 , x=-2
so ( -infinity,-2] [1/3,infinity)   ?

6x^2-24<7x

I got stuck in the quadratic equation

I got to  7+-  square root of -527 all over 12  ?

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x+4 square root of x =5

I attempted to take all the terms to the 4th power to get rid of the square root which gave me

x^4+x=625  ?

Am I right?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: I need a shove in the right direction

Hi;

For the first one your vertex is at ( 5 / 2 , 3 / 2 ). h is correct, what did you do after that?

You should have plugged your h back into f(x) to get 3 / 2.

For the second one your h is correct. Now just plug it back into f(x) to get k.

For the 3rd one:

http://www.mathsisfun.com/algebra/inequ … lving.html

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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.
Always satisfy the Prime Directive of getting the right answer above all else.