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Quadratic Equation solving with Solver 1
- Thread starter newage
- Start date
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1
- #2
Newage:
All I know is this:
Example: you want to solve this equation X^2-X-12=0
Use a cell as a variable e.g. A1.
Use another cell, say B1 as the "target" and put the equation in it. Put =A1^2-A1-12 in B1
before you use the solver the result will, of course, reflect whatever happened to be in A1. If A1 is still null or contains a zero then the result in B1 is -12.
Now go to Tools.. Solver. A dialog will appear
Choose B1 as your target.
Choose A1 as your "By changing cells:"
Where it says "Equal to" set value to 0
Click Solve button.
Your B1 should now contain -4.63155E-09 which is small enough (depending on the precision you choose).
Your A1 now contains the ROOT you are looking for, in this case 4.000000002 ( again not exact but close enough).
I tried this and got both roots (4 and -3) by initiating the value of A1 differently. I use 0 and got -3 and then used +1 and got +4.
I am not sure about complex roots, I will try to play with it later.
All I know is this:
Example: you want to solve this equation X^2-X-12=0
Use a cell as a variable e.g. A1.
Use another cell, say B1 as the "target" and put the equation in it. Put =A1^2-A1-12 in B1
before you use the solver the result will, of course, reflect whatever happened to be in A1. If A1 is still null or contains a zero then the result in B1 is -12.
Now go to Tools.. Solver. A dialog will appear
Choose B1 as your target.
Choose A1 as your "By changing cells:"
Where it says "Equal to" set value to 0
Click Solve button.
Your B1 should now contain -4.63155E-09 which is small enough (depending on the precision you choose).
Your A1 now contains the ROOT you are looking for, in this case 4.000000002 ( again not exact but close enough).
I tried this and got both roots (4 and -3) by initiating the value of A1 differently. I use 0 and got -3 and then used +1 and got +4.
I am not sure about complex roots, I will try to play with it later.
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