/sci/ - Science & Math

[Anonymous No.5006882]

Hey /sci/,

How did they get the (11^(ln11x))(x^(ln11x-1)) in that example?

When I multiply by f(x), all I would get and can get out of it is (2ln11x / x) * (11x^ln11x).

I don't get how/why they seperate the 11 and the x when they multiply by f(x), or how that -1 gets added to the exponent of the x they seperated.

[Anonymous No.5006924]

>>5006882
bumpan, cant find an explanation anywhere

[Anonymous No.5006931]

>(11x^ln11x)

You might want to look at the original expression of f(x) again

[Anonymous No.5007057]

>>5006882

OP - that solution is a right pain in the ass.
It took me a full page of A4 to do it using a longer method; but the answer is correct.

All I can offer is Wolfram
http://www.wolframalpha.com/input/?i=derivative+of+%2811x%29%5Eln11x

But thanks for making me sleepy.

[Anonymous No.5007101]

f(x)(2ln11x / x)

Substitute f(x)
(11x)^ln11x (2ln11x / x)

Expand (11x)^ln11x
11^ln11x x^ln11x (2ln11x / x)

Add the 1/x to the exponent of x
11^ln11x x^ln11x-1 (2ln11x)

Put it in the order of the final answer
2 11^ln11x x^ln11x-1 ln11x

[Anonymous No.5007334]

>>5007101
thanks