SOLUTION: Given that: p²+q²=11pq, where p and q are constants, show that ½(logp+logq) equals: (a) log((p-q)/3) (b) log((p+q)/√3)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Given that: p²+q²=11pq, where p and q are constants, show that ½(logp+logq) equals: (a) log((p-q)/3) (b) log((p+q)/√3)       Log On


   



Question 1124556: Given that: p²+q²=11pq, where p and q are constants, show that ½(logp+logq) equals:
(a) log((p-q)/3)
(b) log((p+q)/√3)

Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
.
Given that: p²+q²=11pq, where p and q are constants, show that ½(logp+logq) equals:
(a) log((p-q)/3)
(b) log((p+q)/√3)
~~~~~~~~~~~~~~~~~


            Notice that the condition  ASSUMES  that  p > 0;  q > 0;  and  p > q,
            although it is not stated explicitly.


(a)   show that  %281%2F2%29%2A%28log%28p%29%2Blog%28q%29%29  equals  log((p-q)/3)

p%5E2+%2B+q%5E2 = 11pq  ====>  subtract 2pq from both sides. You will get  ====>


p%5E2+-+2pq+%2B+q%5E2 = 9pq  ====>


%28p-q%29%5E2 = 9pq  ====>  take the logarithm from both sides ====>


2*log(p-q) = log(9) + log(p) + log(q)


2*log(p-q) - log(3^2) = log(p) + log(q)


2*(log(p-q) - log(3)) = log(p) + log(q)


log((p-q)/3) = %281%2F2%29%2A%28log%28p%29+%2B+log%28q%29%29.

QED

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Your formula in part  (b)  is  INCORRECT.