Use the quadratic formula to solve

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Gr8fu13

Junior Member
Joined
Feb 13, 2011
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123
Directions:
Use the quadratic formula to solve
x^2 - x = -3
How are you suppose to do that when there are x's where there should normally be numbers to fill in the quadratic formula?
I tried and came up with:
x+-square root of 2x - 12 over 2x.
This doesn't make sense to me. This is my last problem I am having trouble with and ofcourse it's not anything like what I have been working with.
Any help would be appreciated. Thanks.
 
Gr8fu13 said:
Directions:
Use the quadratic formula to solve
x^2 - x = -3

Rewrite

1*x[sup:2h8148j6]2[/sup:2h8148j6] - 1*x + 3 = 0

Now use quadratic formula

How are you suppose to do that when there are x's where there should normally be numbers to fill in the quadratic formula?
I tried and came up with:
x+-square root of 2x - 12 over 2x.
This doesn't make sense to me. This is my last problem I am having trouble with and ofcourse it's not anything like what I have been working with.
Any help would be appreciated. Thanks.
Click to expand...
 
I stopped at 1+- square root -11 over 2. From this I can tell that there will be two nonreal complex number solutions (complex conjugates). Would the answer be 1+ square -11 over 2, and 1- square -11 over 2? Or do I need to go further? This would probably mean I would end up with decimals, right?
 
For the answer it says:
The solution set is { }
Type an exact answer, using radicals as needed, express complex numbers as i. Use integers or fractions for any numbers in the expression. Use a comma to seperate answers.

Since it is an EXACT answer they are looking for I would assume the answer would involve root symbols. If it were an approximate answer, it would have decimals, right?
 
Gr8fu13 said:
For the answer it says:
The solution set is { }
Type an exact answer, using radicals as needed, express complex numbers as i. Use integers or fractions for any numbers in the expression. Use a comma to seperate answers.

Since it is an EXACT answer they are looking for I would assume the answer would involve root symbols (and/or fractions). If it were an approximate answer, it would have decimals, right? .... Correct
Click to expand...
 
So the answer would be 1+ square -11 over 2, and 1- square -11 over 2. Is this correct?
 
1+ i square 11 over 2, and 1- i square 11 over 2. Am I getting closer? LOL. I hate math!!
 
That would satisfy me, but, as you can see, I have no idea how to teach.
 
x = [1 +- iSQRT(11)] / 2

SQRT(-11) = SQRT(11 * -1) = SQRT(-1)SQRT(11) : i represents SQRT(-1) : so iSQRT(11)
NOTE: you could have used google and find all that out by yourself :shock:
 
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