Hello all, I need some calc help. It is a 5 question practice test, I answered 2. I need help with the rest..... See attached.

Question

Hello all, I need some calc help.  It is a 5 question practice test, I answered 2.  I need help with the rest.....  See attached.

anonymous · Answer

@amistre64

anonymous · Answer

@AnimalAin @shamil98 @dumbcow

dumbcow · Answer

#1 cant be integrated directly http://www.wolframalpha.com/input/?i=integrate+2%5E%28cos%28x%29%29+dx+from+-3+to+3 same with #2 http://www.wolframalpha.com/input/?i=integrate+sin%28cos%28x%29%2F%28x%5E2+%2B1%29%29dx+from+0+to+6

dumbcow · Answer

#3 can
$$\int\limits e^{-x} -1 = -e^{-x} - x$$

amistre64 · Answer

left hand sums
$$\Large\sum_{i=0}^{n-1} f(a+i\frac{b-a}{n})\frac{b-a}{n}$$
$$\Large\sum_{i=0}^{n-1} f(a+i~\Delta x)\Delta x$$
right hand is just i=1 to n