Posted by Soroban on August 10, 2002 at 12:16:08:
In Reply to: differentiating with logs posted by bana on August 10, 2002 at 00:29:33:
: HI,
: I was wondering if you could tell me if I got this right or wrong.
: y=(2x+3)(3x+4)^2(4x+5)^3
: I have to differentiate by taking logs first , so I got y'=(2x+3)(3x+4)^2(4x+5)^3 * {[2/(2x+3)]+[6/(3x+4)]+ [12/(4x+5)] }
: please correct me and show me the working if i got it wrong.Many thanx.
Absolutely right, bana!
After much simplifying, it becomes:
2(3x+4)(4x+5)^2(72x^2 + 199x + 137)
I even CHECKED the answer using the Extended Product Rule -- and we're fine!