a^x = b^y = c^z ...1
a= b^(y/x) ...2
c= b^(y/z) ...3
ac = b^2 = b^(y/x + y/z) ... multiply 2and 3 and ac = b^2
so take log wrt b
2 = y/x + y/z or 1/x+ 1/z = 2/y
2006-11-18 02:57:11
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answer #1
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answered by Mein Hoon Na 7
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a^x = b^y = c^z
and b^2 = ac
â a^x * c^z = b^y * b^y
â a^x * c^z = b^2y
But b^2 = ac (given).
â a^x * c^z = (ac)^y
â a^x * c^z = a^y * c^y
â x = y and z = y
So: x = y = z
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If x = y = z, then
â a = b = c.
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1/x + 1/z = ?
But: x = z
â 1/x + 1/z = 1/z + 1/z
1/x + 1/z = (z + z)/z²
1/x + 1/z = 2z/z²
1/x + 1/z = 2/z
But x = y = z
â 1/x + 1/z = 2/z = 2/y = 2/x
Answer:
2/z (or) 2/y (or) 2/x
2006-11-18 12:23:10
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answer #2
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answered by Brenmore 5
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2/y
2006-11-18 10:16:38
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answer #3
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answered by mane 5
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first consider the equality a^x=c^z
take logarithms on both the sides
log(a^x)=log(c^z)
a property of logarithms is log(p^q)=q*log(p)
so, log(a^x)=x*log(a) and log(c^z)=z*log(c)
so, xlog(a)=zlog(c)
=> z=x*(loga/logc)
to find 1/x+1/z
substitute the value of z in the above equation in terms of x
1/x+1/x(logc/loga)
=1/x((loga+logc)/loga)-----(1)
now, consider b^2=ac
apply logarithms on both the sides
so, 2logb=loga+logc
substitute in equation (1)
so, 1/x+1/z=1/x(2logb/loga)
=2/x(logb/loga)-----(2)
now consider a^x=b^y
apply logarithms again
xloga=ylogb
=>logb/loga = x/y
substitute this in equation (2)
so, 1/x+1/z=2/x(x/y)
=2/y
since b^2=ac, it implies that a,b and c are in a Geometric Progression (G.P)
since 1/x+1/z=2/y, it implies that x,y and z are in a Harmonic Progression (H.P)
2006-11-18 10:21:27
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answer #4
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answered by sameer 2
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please make your own homework
2006-11-18 10:11:40
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answer #5
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answered by Anonymous
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