document.write( "Question 92522This question is from textbook The Road to Reality
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document.write( ": I find it difficult to grasp the idea of 'x raised to the power i (or multiple of i', or indeed 'x raised to the power of a general complex number'. I can understand 2^3, 3^0.5 etc., but what is the meaning of, say, 3^i, 3^(2+3i) etc. What are, say, '3^i', '3^(2+3i)', and why? How does this relate to Euler's formula? \r
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document.write( "The problem comes from reading 'The Road to Reality' by Roger Penrose, ISBN no 0-224-04447-8, p90 (section 5.2 entitled 'The Idea of the Complex Logarithm'). Real logarithms - OK: complex ones I just can't quite grasp. \n" );
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Algebra.Com's Answer #67358 by Nate(3500) ![]() You can put this solution on YOUR website! Euler's formula is based upon the natural number, e. Also, the formula is really the only explanation of having a complex power. \n" ); document.write( "While e^(xi) is given, we can manipulate it. \n" ); document.write( "e^(xi) \n" ); document.write( "(e^x)^i \n" ); document.write( "Where as: e^x = 3 ~> x = ln(3) \n" ); document.write( "Then: \n" ); document.write( "e^(ln(3)*i) = cos(ln(3)) + sin(ln(3))i \n" ); document.write( "~~~~ \n" ); document.write( "This relates to Euler's formula greatly as you may see.... \n" ); document.write( "This may help you: \n" ); document.write( "Suggest that: p = cos(x) + sin(x)i \n" ); document.write( "dp / dx = -sin(x) + cos(x)i \n" ); document.write( "dp / dx = i^2*sin(x) + cos(x)i \n" ); document.write( "dp / dx = [i*sin(x) + cos(x)]i \n" ); document.write( "dp / dx = pi \n" ); document.write( "(1 / p) dp / dx = i \n" ); document.write( "ln(p) = xi + C \n" ); document.write( "p = e^(xi + C) \n" ); document.write( "cos(x) + sin(x)i = e^(xi + C) \n" ); document.write( "cos(x) + sin(x)i = e^(xi) ~~~> using (0,1) as in (x,p) \n" ); document.write( " |