Saturday, February 16, 2013

Solve the equation 1/2^(x^2-1)=square root(16^x).

We'll manipulate the left side using the negative power
property:


1/2^(x^2-1)=2^-(x^2-1)


Now,
we'll manipulate the right side, writting 16 as a power of
2:


sqrt(16^x) = sqrt(2^4x) = (2^4x)^(1/2) =
2^2x


We'll re-write the
equation:


2^-(x^2-1) =
2^2x


Since the bases are matching now, we'll apply one to
one property:


-x^2+1 = 2x


x^2
+ 2x - 1 = 0


x1 = [-2+sqrt(4 +
4)]/2


x1 = (-2+2sqrt2)/2


x1 =
-1+sqrt2


x2 =
-1-sqrt2


The solutions of exponential
equation are { -1-sqrt2 ; -1+sqrt2}.

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