How are these wrong?

Question

anonymous · Answer

attachment

anonymous · Answer

attachment

anonymous · Answer

take a look and let me know, I thought I did all the math correct

anonymous · Answer

When you do Riemann sum you are taking the area of the rectangle formed ... it says to take the left Riemann sum so you go up till the left corner hits the graph and then find the area ... you will have 4 rectangles (4 sub divisions)

anonymous · Answer

right, I did the left Riemann for 4 rectangles from [2, 10] and got 12, yet it's wrong

anonymous · Answer

The width of each rectangle should be 2 

Here is the set of points you should have for each corner:

t      n(t)
2     0.5
4     1.5
6     0
8     1

anonymous · Answer

that's what I got... I'm just an idiot, don't mind me

anonymous · Answer

I figured out where I went wrong

anonymous · Answer

Your not an idiot ... part of learning

anonymous · Answer

haha thanks, what about my other problem that says it's wrong?

anonymous · Answer

I'm like 98% sure that's supposed to be correct

anonymous · Answer

I will try an solve

anonymous · Answer

thanks

anonymous · Answer

That is correct it probably wants you to place the number as a fraction

anonymous · Answer

ah thanks