1. ## second derivative problem

second derivative problem

2. Originally Posted by afeasfaerw23231233
second derivative problem
You can if you are confident of getting it right, but I would not and under
certain condition you might lose marks (like if you are asked to show
a result that you could work backwards from to something that you jump
to with little explanation).

RonL

3. Originally Posted by afeasfaerw23231233
second derivative problem
I recommend writing out all the steps even if you are experienced. Even the "masters" can make mistakes and showing all your work is an excellent way to help you catch or find those. (Hey, I do it and I still make mistakes every now and again!)

-Dan

4. i only want to know if there are some 'way' to do it quickly without writing the full expansion, or some way for me to do the mental calculation. for example, by the identity a^3 + b^3 = (a + b) (a^2 - ab + b^2), i do not need to do all the expansion when i meet a similar pattern in a question. i am afraid that i won't have enough time in the exam. but thanks for your advice anyway

5. maybe there are some tricks and technique that i don't know so that i do it slow?

6. Originally Posted by afeasfaerw23231233
maybe there are some tricks and technique that i don't know so that i do it slow?
The only thing I can add is that I probably would have skipped from step 1 to 3 directly. For the rest there's too many chances of distributing incorrectly or sign errors. (In my opinion.)

-Dan