document.write( "Question 846997: X^4+x^2+1=0 \n" ); document.write( "
Algebra.Com's Answer #510184 by josh_jordan(263)\"\" \"About 
You can put this solution on YOUR website!
This is quite the complex problem! So, let's get started.\r
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\n" ); document.write( "\n" ); document.write( "If we rewrite \"x%5E4%2Bx%5E2%2B1=0\" in the form of a quadratic equation, we will be able to find our zeroes. We can do this by rewriting as:\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%5E2%29%5E2%2B%28x%29x%2B1=0\"\r
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\n" ); document.write( "\n" ); document.write( "This puts our equation in standard quadratic form of ax^2+bx+c=0. Now, we can replace the first x inside the parenthesis with a letter and replace the second x on the outside of the parenthesis with the same letter. Let's use u:\r
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\n" ); document.write( "\n" ); document.write( "\"u%5E2%2Bu%2B1=0\"\r
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\n" ); document.write( "\n" ); document.write( "Now we can solve using the quadratic formula. This will give us:\r
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\n" ); document.write( "\n" ); document.write( "\"u=%28-1+%2B-+sqrt%28+-3+%29%29%2F%282%29+\"\r
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\n" ); document.write( "\n" ); document.write( "Now, here comes the tricky part. We have to replace our u with our original variable and power: x^2, which will turn this into:\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2=%28-1+%2B-+sqrt%28+-3+%29%29%2F%282%29+\"\r
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\n" ); document.write( "\n" ); document.write( "Because we want the value of x and not x^2, we will have to take the square root of both sides. Remember, when we take the square root of both sides of an equation, we have to add the +- sign in front. Doing this is going to give us 4 zeros:\r
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\n" ); document.write( "\n" ); document.write( "\"x=+%2B-+%28sqrt%28%28-1+%2B-+sqrt%28+-3+%29%29%2F%282%29%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "Next, you will want to convert the square root of -3 into an imaginary:\r
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\n" ); document.write( "\n" ); document.write( "\"x=+%2B-+%28sqrt%28%28-1+%2B-+sqrt%28+3+%29%2Ai%29%2F%282%29%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "Finally, you will need to rationalize the denominator since the denominator of the fraction is the square root of 2. This will give you your final answer:\r
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\n" ); document.write( "\n" ); document.write( "\"x=+%2B-+%28sqrt%28%282%28-1+%2B-+sqrt%28+3+%29%2Ai%29%29%29%2F%282%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "For some reason, the answer typed out the word \"PLUS_MINNUS-\" instead of \"+-\". Just replace the \"PLUS_MINNUS-\" with the plus/minus symbol (+-).\r
\n" ); document.write( "\n" ); document.write( "NOTE: You will notice the numerator of the fraction contains a square root inside of a square root (nested root). You will more than likely not be required to denest this root, so it was not denested in this solution.
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