how can i solve Y = A + B1X + B2X^2+B3X^3+B4X^4 in excel work sheet? I have Y, B1, B2, B3, B4, A values!?

Question

I have to find the value of x.

Answer 1

You can use the command Goal Seek. In a cell, say A1, you put the value for x. In another you put the formula = A + B1*A1 + B2*A1^2+B3*A1^3+B4*A1^4. Of course, the coefficients must be in cells. Then you call Goal Seek. You'll open a window and it's be evident how to use it.

But Goal Seek only find real roots. And since your polynomial may have more than one real root, you'll have to vary the initial estimate to find all roots.

Like Chrispophe said, before using Goal Seek you should graph the function, to get an idea about where they are located.

Answer 2

I would graph the function to estimate where the roots are then you could use a dichotomy method.

Answer 3

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