Answer:
C
Step-by-step explanation:
An approximation of an integral is given by:

First, find Δx. Our a = 2 and b = 8:

The left endpoint is modeled with:

And the right endpoint is modeled with:

Since we are using a Left Riemann Sum, we will use the first equation.
Our function is:

Therefore:

By substitution:

Putting it all together:

Thus, our answer is C.
*Note: Not sure why they placed the exponent outside the cosine. Perhaps it was a typo. But C will most likely be the correct answer regardless.
Answer:
Width: 6 cm
Length: 9 cm
Step-by-step explanation:
Width: x
Length: x + 3
2(x)+2(x+3) = 30cm
2x + 2x + 6 = 30
4x = 30-6
x = 24/4
x = 6
Answer 2,290 of total sheets of paper she bought.
Step-by-step explanation:
65x36=2340
subtract 50 for the black pages that she did not use.
2340-50=2,290