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I don't see the stupid questions thread so here goes.
(0.625)^126 < (2.56)^(-3x)
What the fuck is this problem. I've been sitting with this problem for two days now and I still can't solve it. Here's what I tried to do:
(0.625)^126 < (2.56)^(-3x)
(2.56)^-2(126) < (2.56)^(-3x)
(2.56)^-252 < (2.56)^(-3x)
-252 < -3x
84 > x
and I get the interval (- infinity, 84).
But the solution is apparently (- infinity, 21) and Wolfram Alpha shows that too but I don't understand why. What am I doing wrong?
https://www.wolframalpha.com/input/?i=(0.625)%5E126+%3C+(2.56)%5E(-3x)
>>
2.56^-2 != .625
2.56^(1/2) = .625
When it comes down to checking things like this the last resort is to use a calculator to check each and every step so as to isolate the step where a step was made.
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>>8457414
You can also use this method to isolate the region where the wrong step was made.
For very long integrals you can check the first half, then the first quarter, then etc...
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>>8457414
Thank you, I can't believe I made such a stupid mistake.
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I need help with computing a basic integral, that I don't understand how to do
[math]\int\frac{1}{(x^2+1)^2}dx[/math]
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>>8457837
[math]\int\frac{1}{(x^2+1)^2}dx[/math]
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