Monday, April 21, 2014

a^x =b^y = c^z = abc ; find 1/x + 1/y + 1/z

Taking logs then dividing we can see that... 

x=ln%28abc%29%2Fln%28a%29 
from which we deduce 
1%2Fx=ln%28a%29%2Fln%28abc%29 
similarly 
1%2Fy=ln%28b%29%2Fln%28abc%29
and
1%2Fz=ln%28ac%29%2Fln%28abc%29 
therefore 
1%2Fx%2B1%2Fy%2B1%2Fz=%28ln%28a%29%2Bln%28b%29%2Bln%28c%29%29%2Fln%28abc%29=1 
i.e. 
1%2Fx%2B1%2Fy%2B1%2Fz=1

No comments: