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View Full Version : Short but complicated as fuck indices problem


MrSparkle
2009-01-11, 05:20
Solve for x
2^x + 1 = 3^(2x - 1)

Can anyone help me out with this one? I was thinking about trying to convert it to logs then changing the base so I can clean the fuckin thing up a bit but how I can't even figure out how to change something like that to logs.

EDIT: Fuck I just thought about plugging some random values into it and the first one I plugged in (1) was the answer. Would you say thats what they wanted me to do or was I meant to do some long method to solve it? This is a test question worth 20 marks (some questions that take 15 minutes to answer are only worth 15)

Shadout Mapes
2009-01-11, 19:17
There's no way to explicitly solve for x in an equation like that, the problem probably wanted you to guess numbers. Generally when solving such a problem one would use the Newton-Raphson Method or something similar to obtain a good approximation, but you'd have to be given a calculator so you could just guess or graph it or whatever your preferred method.