document.write( "Question 379999: Please help me! I am stuck and don't know if I'm doing this right and it's due tomorrow!!! I am confused when I am letting y=0 and solving for x using the quadratic formula... that is where I get stumped. \r
\n" ); document.write( "\n" ); document.write( "y=x^2-2x-2\r
\n" ); document.write( "\n" ); document.write( " I need to find the vertex and any two convenient points to sketch the graph. This is what I've done so far and I will note when I get confused.\r
\n" ); document.write( "\n" ); document.write( "Letting y=0
\n" ); document.write( "{0=-(2)+- sqrt(-2)^2-4(1)(2)all over 2}
\n" ); document.write( "then I end up with
\n" ); document.write( "{x=2+- sqrt(-4)} over 2\r
\n" ); document.write( "\n" ); document.write( "I do not know where to get next. Do I divide the 2 into the 2 and 4? Then that would give me -1 +- 2 right??? Then I would set them to zero and have my x points?\r
\n" ); document.write( "\n" ); document.write( "I have solved for y by letting x=0
\n" ); document.write( "y=o^2-2(0)-2
\n" ); document.write( "y=-2
\n" ); document.write( "(0,-2)\r
\n" ); document.write( "\n" ); document.write( "I have found the vertex by using: x=b/2(a)
\n" ); document.write( "x=2/2(1) y=(1)^2-2(1)-2
\n" ); document.write( "x=1 y= -3 giving me plots of (1,-3)\r
\n" ); document.write( "\n" ); document.write( "I really hope someone can help me. I know it is late but I have run out of resources. Thanks D.
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Algebra.Com's Answer #269733 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-2x-2=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"x%5E2-2x-2\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=1\", \"B=-2\", and \"C=-2\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"x\":\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-2%29+%29%29%2F%282%281%29%29\" Plug in \"A=1\", \"B=-2\", and \"C=-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-2%29+%29%29%2F%282%281%29%29\" Negate \"-2\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4-4%281%29%28-2%29+%29%29%2F%282%281%29%29\" Square \"-2\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4--8+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-2%29\" to get \"-8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4%2B8+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%284--8%29\" as \"sqrt%284%2B8%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+12+%29%29%2F%282%281%29%29\" Add \"4\" to \"8\" to get \"12\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+12+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+2%2Asqrt%283%29%29%2F%282%29\" Simplify the square root (note: If you need help with simplifying square roots, check out this solver) \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282%29%2F%282%29+%2B-+%282%2Asqrt%283%29%29%2F%282%29\" Break up the fraction. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+1+%2B-+sqrt%283%29\" Reduce. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+1%2Bsqrt%283%29\" or \"x+=+1-sqrt%283%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x+=+1%2Bsqrt%283%29\" or \"x+=+1-sqrt%283%29\" \r
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\n" ); document.write( "\n" ); document.write( "Since these values approximate to \"x=2.73205081\" or \"x=-0.732050808\", the x-intercepts are approximately (2.73205081, 0) and (-0.732050808, 0)\r
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\n" ); document.write( "\n" ); document.write( "You have the correct vertex and y-intercept.\r
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\n" ); document.write( "\n" ); document.write( "If you need more help, email me at jim_thompson5910@hotmail.com\r
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\n" ); document.write( "\n" ); document.write( "Also, feel free to check out my tutoring website\r
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\n" ); document.write( "\n" ); document.write( "Jim
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