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).
1 billion is 1,000 million 1,000,000,000
so
27,003,095,000
2π is the period of `y = 1+ tan((1)/(2)x)`
Answer:
B
Step-by-step explanation:
it is the opposite of A, which is true, as |-8| = 8