Tuesday, February 19, 2013

What are the roots of the equation 16^x-3*4^x+2=0?

We'll write 16 = 4^2.


We'll
re-write the equation in this manner:


(4^2)^x - 3*4^x + 2 =
0


We'll substitute 4^x by the variable,
t.


t^2 - 3t + 2 = 0


We'll
apply quadratic formula for finding t:


t1 = [3+sqrt
(9-4*2)]/2*1


t1 = [3+sqrt
(1)]/2


t1 =
(3+1)/2


t1 =
2


t2 =
(3-1)/2


t2 =
1


We'll find the values of x,
now.


4^x =
t1


4^x=2


We'll write 4^x =
2^2x


2^2x = 2^1


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


2x =
1


x =
1/2


4^x =
t2


4^x = 1


4^x =
4^0


x =
0


The solutions of the
equation are {0 ; 1/2}.

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