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# How to Solve[] for a negative exponent?

Posted 9 years ago
 How can I solve for 'x'? I tried the following, Solve[0.3^-x == 1, x]  NSolve[0.3^-x == 1, x]  The answer should be close to -2/11ths, 0.3^-2/11==1.0101  I'm interested in getting this specific form, of solving for a negative exponent, to work, rather than this example problem. Much thanks for help!
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Posted 9 years ago
 The answer is 0 In[64]:= 0.3^0 Out[64]= 1. because the right hand side is 1. More general In[74]:= Solve[1/0.3^x == 1/817, x, Reals] During evaluation of In[74]:= Solve::ratnz: Solve was unable to solve the system with inexact coefficients. The answer was obtained by solving a corresponding exact system and numericizing the result. >> Out[74]= {{x -> -5.56959}} In[75]:= NSolve[0.3^(-x) == 1/817, x, Reals] During evaluation of In[75]:= Solve::ratnz: Solve was unable to solve the system with inexact coefficients. The answer was obtained by solving a corresponding exact system and numericizing the result. >> Out[75]= {{x -> -5.56959}} In[76]:= Rationalize[0.3^(-x) /. %75[[1, 1]]] Out[76]= 1/817 
Posted 9 years ago
 smart- thanks