MQ18 --- Exponential Equation

2012-05-27 7:51 pm
Difficulty: 70%Solve xˣ = 2x.

回答 (6)

2012-05-30 12:35 am
I know.

But how to get exact value?

2012-05-29 17:41:49 補充:
Graphical method cant get exact value.

2012-05-31 22:01:01 補充:
Maybe this shouldn't be MQ18...
2012-05-30 12:28 am
One is 2, another is around 0.346323

2012-05-29 17:03:05 補充:
Using bisection method, plot two graph, y = 1/(x-1) and y = log x / log 2,
one of the intersection point is 2 and the other lies between 0 and 1.
2012-05-29 4:02 am
I'll try only.
xˣ= 2x
x^(x-1)=2
(x-1)log2(x)=1
because x ∈ C
so x-1=1, and log2(x)=1
x=2

sorry if it is wrong
2012-05-28 8:42 am
Maybe finding approximate solutions for the equation is more practical.
2012-05-28 7:41 am
Solving in R or in C will be very different. State exactly what you want.


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