Changing equation to standard form

It is -x^2- 2x+ 2, not -x^2+ 2x+ 2. The correct completed square form is -(x+1)^2+3.In summary, the conversation discusses completing the square for two given equations and finding the points of intersection of their graphs. The first equation is completed by factoring out a negative sign, while the second equation requires slightly more steps due to its negative values. It is eventually completed as -(x+1)^2+3.
  • #1
renob
89
0

Homework Statement



Sketch the region in the xy-plane that is bounded between the graphs of the given functions. Find the points of intersection of the graphs.

1) y=x^2+2x+2

2)y=-x^2-2x+2

The Attempt at a Solution



I already completed the square for equation 1):
y=(x+1)^2+1

Im having trouble completing the square for the second equation because of the negative values. I tried factoring out the negative sign:

-(x^2+2x-2)

but that just makes the 2 negative.

How should I go about converting the second equation?
 
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  • #2
nevermind, i got it
 
  • #3
Oh well from what i can see,-x^2-2x+2 = -(x^2+2x+2) +4. so...-x^2-2x+2=-(y)+4. If you can sketch the graph for the 1st one the second one shouldn't be a problem:biggrin:
 
  • #4
renob said:

Homework Statement



Sketch the region in the xy-plane that is bounded between the graphs of the given functions. Find the points of intersection of the graphs.

1) y=x^2+2x+2

2)y=-x^2-2x+2


The Attempt at a Solution



I already completed the square for equation 1):
y=(x+1)^2+1

Im having trouble completing the square for the second equation because of the negative values. I tried factoring out the negative sign:

-(x^2+2x-2)
No, [itex]-(x^2+ 2x- 2)= -x^2- 2+ 2[/itex], not [itex]x^2- 2x+ 2[/itex].
[itex]x^2- 2x+ 2= (x- 1)^2+ 1[/itex].

but that just makes the 2 negative.

How should I go about converting the second equation?
 
  • #5
hmm did i make a mistake somewhere? Where did the [itex] x^2- 2x+ 2 [/itex] come from haha::rolleyes:
 
  • #6
it comes out to be -(x+1)^2+3
 
  • #7
HallsofIvy said:
No, [itex]-(x^2+ 2x- 2)= -x^2- 2+ 2[/itex], not [itex]x^2- 2x+ 2[/itex].
[itex]x^2- 2x+ 2= (x- 1)^2+ 1[/itex].

I think you misread the second equation
 

What is the standard form of an equation?

The standard form of an equation is a way of writing an equation in a specific and consistent format. In general, standard form for linear equations is written as Ax + By = C, where A, B, and C are constants and x and y are variables.

Why is it important to change equations to standard form?

Changing equations to standard form makes it easier to compare and solve equations. It also allows for easier identification of important characteristics of the equation, such as the slope and y-intercept.

How do you change an equation to standard form?

To change an equation to standard form, you need to manipulate and rearrange the equation so that it follows the format of Ax + By = C. This can involve distributing coefficients, combining like terms, and moving terms to the opposite side of the equation.

Can all equations be written in standard form?

No, not all equations can be written in standard form. This format is typically used for linear equations, which have a constant rate of change. Non-linear equations, such as quadratic or exponential equations, cannot be written in standard form.

What are the benefits of using standard form for equations?

The benefits of using standard form for equations include easier comparison and solving of equations, clearer identification of key components, and the ability to graph equations more easily. It also allows for consistency and organization when working with multiple equations.

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