document.write( "Question 623928: I need someone help i am stuck doing this last part of my homework. can someone explain it to me \r
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\n" ); document.write( "\n" ); document.write( "Match each equation for a parabola with the direction that the parabola opens.\r
\n" ); document.write( "\n" ); document.write( "1. y=-3(x+1)^2-8
\n" ); document.write( "2. x=-3(y+1)^2-8
\n" ); document.write( "3. y=3(x+1)^2-8
\n" ); document.write( "4. x=3(y+1)^2-8\r
\n" ); document.write( "\n" ); document.write( "A. up
\n" ); document.write( "B. right
\n" ); document.write( "C. down
\n" ); document.write( "D. left \r
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Algebra.Com's Answer #392414 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
if y = x^2, then the parabola will open up.
\n" ); document.write( "if y = -x^2, then the parabole will open down.
\n" ); document.write( "if x = y^2, then the parabola will open to the right.
\n" ); document.write( "if x = -y^2, then the parabole will open to the left.
\n" ); document.write( "what we are dealing with is the coefficient of the squared term.
\n" ); document.write( "your equations are:
\n" ); document.write( "1. y=-3(x+1)^2-8
\n" ); document.write( "2. x=-3(y+1)^2-8
\n" ); document.write( "3. y=3(x+1)^2-8
\n" ); document.write( "4. x=3(y+1)^2-8
\n" ); document.write( "(x+1)^2 will be equal to x^2 + 2x + 1
\n" ); document.write( "(y+1)^2 will be equal to y^2 + 2y + 1
\n" ); document.write( "your equations therefore become:
\n" ); document.write( "1. y = -3(x^2 + 2x + 1) - 8
\n" ); document.write( "2. x = -3(y^2 + 2y + 1) - 8
\n" ); document.write( "3. y = 3(x^2 + 2x + 1) - 8
\n" ); document.write( "4. x = 3(y^2 + 2y + 1) - 8
\n" ); document.write( "remove parentheses and simplify to get:
\n" ); document.write( "1. y = -3x^2 - 6x - 11
\n" ); document.write( "2. x = -3y^2 - 6y - 11
\n" ); document.write( "3. y = 3x^2 + 6x - 5
\n" ); document.write( "4. x = 3y^2 + 3y - 5
\n" ); document.write( "when determining whether the parabole will open up or down, the only meaningful consideration is the sign of the coefficient of the squared term.
\n" ); document.write( "based on this, you should get the following answers.
\n" ); document.write( "1. will open down
\n" ); document.write( "2. will open to the left.
\n" ); document.write( "3. will open up.
\n" ); document.write( "4. will open to the right.
\n" ); document.write( "we can graph these equations and see how we did.
\n" ); document.write( "to graph these equations, you have to solve for y in all equations.
\n" ); document.write( "the original equations are:
\n" ); document.write( "1. y=-3(x+1)^2-8
\n" ); document.write( "2. x=-3(y+1)^2-8
\n" ); document.write( "3. y=3(x+1)^2-8
\n" ); document.write( "4. x=3(y+1)^2-8
\n" ); document.write( "equations 1 and 3 can be graphed as is.
\n" ); document.write( "you need to solve for y in equations 2 and 4.
\n" ); document.write( "equation 2 is:
\n" ); document.write( "x = -3(y+1)^2 - 8
\n" ); document.write( "add 3(y+1)^2 to both sides of this equation and subtract x from both sides of this equation to get:
\n" ); document.write( "3(y+1)^2 = -x - 8
\n" ); document.write( "divide both sides of this equation by 3 to get:
\n" ); document.write( "(y+1)^2 = (-x-8)/3 which is the same as:
\n" ); document.write( "(y+1)^2 = -(x+8)/3
\n" ); document.write( "take the square root of both sides of this equation to get:
\n" ); document.write( "y+1 = +/- ( -(x+8)/3 )
\n" ); document.write( "subtract 1 from both sides of this equation to get:
\n" ); document.write( "y = -1 +/- sqrt( -(x+8)/3 )
\n" ); document.write( "equations to graph for equation 2 are:
\n" ); document.write( "y = -1 + sqrt( -(x+8)/3 )
\n" ); document.write( "y = -1 - sqrt( -(x+8)/3 )
\n" ); document.write( "equation 4 is:
\n" ); document.write( "x = 3(y+1)^2 - 8
\n" ); document.write( "add 8 to both sides of this equation to get:
\n" ); document.write( "3(y+1)^2 = x + 8
\n" ); document.write( "divide both sides of this equation by 3 to get:
\n" ); document.write( "(y+1)^2 = (x+8)/3
\n" ); document.write( "take the square root of both sides of this equation to get:
\n" ); document.write( "y+1 = +/- sqrt( (x+8)/3 )
\n" ); document.write( "subtract 1 from both sides of this equation to get:
\n" ); document.write( "y = -1 +/- sqrt( (x+8)/3 )
\n" ); document.write( "equations to graph for equation 4 are:
\n" ); document.write( "y = -1 + sqrt( (x+8)/3 )
\n" ); document.write( "y = -1 - sqrt( (x+8)/3 )
\n" ); document.write( "graph of equation 1 is:
\n" ); document.write( "\"graph%28600%2C600%2C-5%2C5%2C-30%2C30%2C-3%28x%2B1%29%5E2-8%29\"
\n" ); document.write( "graph of equation 2 is:
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\n" ); document.write( "graph of equation 3 is:
\n" ); document.write( "\"graph%28600%2C600%2C-5%2C5%2C-30%2C30%2C3%28x%2B1%29%5E2-8%29\"
\n" ); document.write( "graph of equation 4 is:
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