hi

i am lost in this question. please help:

http://img510.imageshack.us/img510/9...15918amux8.png

thanks

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- February 19th 2009, 10:30 PMchamprockLimits question
hi

i am lost in this question. please help:

http://img510.imageshack.us/img510/9...15918amux8.png

thanks - February 19th 2009, 11:12 PMmollymcf2009
- February 20th 2009, 12:52 AMchamprock
isnt the differentiation of

wrong? wont we have to apply the chain rule in this so it will become:

[( 3^x * ln 3 ) + (3^2x * ln 3 * 2) ] / [3^x +3^2x) ? - February 20th 2009, 04:43 AMmr fantastic
- February 20th 2009, 05:33 AMchamprock

Applying that rule to the above gives (3^x * ln 3) / (1 + 3^x) . Now, I take ln 3 out of the limit and add and subtract 1 from numerator.

So it becomes 3* ln3 * lim [1 - 1/(1+3^x) ] .

Now the 1/(1+3^x) is zero when we apply limit to the above so, it becomes ln y = ln 3^3 the answer thus comes as 27 whcih is not even given as an option. - February 20th 2009, 05:37 AMmr fantastic
- February 20th 2009, 05:55 AMPlato
Does this suprise you?