Regarding the issue of reversing Excel functions
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Are there any forum members who are familiar with Excel? I would like to ask a question regarding function evaluation. For example, y = x + x squared + the square root of x. I can calculate y based on x, but what if I want to determine the value of x based on y? Can Excel do calculations?
Enter the value of x in cell A1 (assume a positive number for now, such as 4), and enter the formula for calculating y in cell A2: “=x^2+x^0.5”. Click sequentially on Data > Simulation Analysis > Single Variable Solving. Select A2 as the target cell, enter the Y value you have set in the target value field, select A1 as the variable cell, and click OK. The result of A1 is the x you are asking for. Done.
The method is feasible, but it seems to only yield approximate solutions rather than exact ones.
Excel can only provide solutions in decimal form; since the result is an infinite non-repeating decimal, rounding is necessary. If a smaller error level is required, iterative calculation can be enabled in File > Options > Formulas, where the calculation error can be set. (I believe that for problems like yours, it’s impossible for a computer to arrive at an exact solution; there will always be some degree of error.) Because it cannot handle irrational numbers such as “sqrt(2) + sqrt(2);” instead, it has to convert them into rational numbers like “1.414 + 1.414” in order to perform calculations. My knowledge is limited; I’m not sure if what I say is correct
There are indeed many experts in Haichuanli, thank you