Step-by-step explanation:
A left Riemann sum approximates a definite integral as:

Given ∫₂⁸ cos(x²) dx:
a = 2, b = 8, and f(x) = cos(x²)
Therefore, Δx = 6/n and x = 2 + (6/n) (k − 1).
Plugging into the sum:
∑₁ⁿ cos((2 + (6/n) (k − 1))²) (6/n)
Therefore, the answer is C. Notice that answer D would be a right Riemann sum rather than a left (uses k instead of k−1).
9.09% increase.
First find the difference between the two numbers.
(4)
then, divide the result by the original amount...
4÷ 44
then multiply by 100
9.09 and that is to the nearest 10th otherwise your answer 9% increase from 44 to 48.
Answer:
...........
Step-by-step explanation:
...........
To solve 4n you need to divide both sides by 4