Hi I have problems integrating two questions, how do I integrate sqrt(x^2-4) / x? And (4lnx) / (x(1+(lnx)^2)? Thank you very much!!
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For the second problem, first use t= ln(x), then use z = 1+ t^2. Hope this helps!
Hello, Tutu! It should be obvious that a Trig Substitution is called for. Let Substitute: . . . . . . . . . Now back-substitute.
Originally Posted by coolge For the second problem, first use t= ln(x), then use z = 1+ t^2. Hope this helps! Which is, of course, the same as the single substitution z= 1+ (ln(x))^2.
Originally Posted by HallsofIvy Which is, of course, the same as the single substitution z= 1+ (ln(x))^2. My two cents. I prefer to use two separate substitutions rather than one more complicated one. I can keep better track that way. Or maybe I'm just a coward. -Dan
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