We'll re-write the
equation:
10*10^(x^2) - 10/10^(x^2) - 99 =
0
We'll replace 10^(x^2) by
t:
10*t - 10/t - 99 = 0
10t^2
- 99t - 10 = 0
We'll apply quadratic
formula:
t1 =
[99+sqrt(9801+400)]/20
t1 =
(99+101)/20
t1 = 10
t2 =
(99-101)/20
t2 = -0.1
But
10^(x^2) = t1 <=> 10^(x^2) = 10
Since the
bases are matching, we'll apply one to one rule:
x^2 = 1
<=> x1 = -1 and x2 = 1
10^(x^2) = t1
<=> 10^(x^2) =-0.1 ,
impossible.
The possible solutions of the
equation are: {-1 ; 1}.
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