B Is there a formula to get x in Excel without using solver: 0.5^x+0.2^x+0.25^x=1

  • B
  • Thread starter Thread starter The Investor
  • Start date Start date
  • Tags Tags
    Excel Formula
AI Thread Summary
The equation 0.5^x + 0.2^x + 0.25^x = 1 lacks a neat formula for solving for x. There is no analytic solution, making it a non-standard problem. Iterative approaches are necessary, which can be implemented using Excel's solver, macros, or methods like Newton's method within Excel cells. Ultimately, Excel does not provide a straightforward formula for this equation. Therefore, alternative computational methods are required to find the solution.
The Investor
Messages
34
Reaction score
0
TL;DR Summary
Hi! I wanted to see if there is a formula to get x in excel without using solver: 0.5^x+0.2^x+0.25^x=1. Thanks!
0.5^x+0.2^x+0.25^x=1.
 
Mathematics news on Phys.org
I don't think there is a neat formula for x.
https://www.wolframalpha.com/input/?i=0.5^x+0.2^x+0.25^x=1

1602626567806.png
 
  • Like
Likes morrobay and berkeman
There is no analytic solution to it and it's not a standard problem, so you need some sort of iterative approach. You can do that with the solver, you can write a macro to do it, you can even do it in some Excel cells (e.g. using the Newton method), but Excel won't have a nice formula for it.
 
  • Like
Likes berkeman
OK, that's what I thought. Cheers guys.
 
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
Is it possible to arrange six pencils such that each one touches the other five? If so, how? This is an adaption of a Martin Gardner puzzle only I changed it from cigarettes to pencils and left out the clues because PF folks don’t need clues. From the book “My Best Mathematical and Logic Puzzles”. Dover, 1994.

Similar threads

Replies
5
Views
2K
Replies
1
Views
2K
Replies
19
Views
1K
Replies
16
Views
4K
Replies
15
Views
3K
Replies
1
Views
655
Replies
2
Views
1K
Back
Top