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.