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3 Answers
t=√2
v=√2+1
tx + vx =(t2+v2)x/2
x=2 is one root.. i cant see others but then I may be wrong!
If we write as (t2)x/2+(v2)x/2 = (t2+v2)x/2 and set x/2 = y,
the equation becomes
ay+by=(a+b)y
Dividing by by, we get
1+ky = (1+k)y where 0< k = a/b<1
We will prove that equality occurs only when y = 1
Suppose y<0, then LHS>1 but RHS<1 so equality cannot occur
Consider f(y) = (1+k)y-ky -1
For y>0, (1+k)y increases monotonically.
ky decreases monotonically (k<1), so that -ky increases monotonically
Now we can therefore infer that (1+k)y-ky -1 is a monotnically increasing continuous function
f(0) = -1, f(1) = 0. Thus f(y)<0 for 0≤y<1 and f(y)>0 for y>1
Hence there are no solutions other than y = x/2 = 1. Hence x =2 is the only solution