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).
Answer:
<h2>$4.7</h2>
Step-by-step explanation:
step one:
Let the cost be y
to solve for the cost of a movie ticket, we need to solve the expression
y=2.75+0.10x
step two:
given that x is the number of years between 1980-2000
the number of years is 20years
put x= 20 in the expression for the cost we have
y=2.75+0.10(20)
y=2.7+2
y=$4.7
You only need a common denominator for adding and subtracting! <span />
Step-by-step explanation:
You have found a function r(V(t)). We can see that this function is a one variable function. The variable is time.
So in this specific function we can call r(v(t)), r(t).
So:
![r(t) = \sqrt[3]{ \frac{3 \times (10 + 20t)}{4\pi} }](https://tex.z-dn.net/?f=r%28t%29%20%3D%20%20%5Csqrt%5B3%5D%7B%20%5Cfrac%7B3%20%5Ctimes%20%2810%20%2B%2020t%29%7D%7B4%5Cpi%7D%20%7D%20)
If α is the moment that the radius is 10 inches and since the function above gives radius in inches we have to solve the equation:

Which is the same as:
![\sqrt[3]{ \frac{3 \times (10 + 20 \alpha )}{4\pi} } = 10 \\ \frac{3 \times (10 + 20 \alpha )}{4\pi} = 1000 \\ (10 + 20 \alpha ) = \frac{4000\pi}{3} \\ 20 \alpha = \frac{(4000\pi - 30)}{3} \\ \alpha = \frac{(4000\pi - 30)}{60}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B%20%5Cfrac%7B3%20%5Ctimes%20%2810%20%2B%2020%20%5Calpha%20%29%7D%7B4%5Cpi%7D%20%7D%20%20%3D%2010%20%5C%5C%20%20%5Cfrac%7B3%20%5Ctimes%20%2810%20%2B%2020%20%5Calpha%20%29%7D%7B4%5Cpi%7D%20%20%3D%201000%20%5C%5C%20%2810%20%2B%2020%20%5Calpha%20%29%20%3D%20%20%5Cfrac%7B4000%5Cpi%7D%7B3%7D%20%20%5C%5C%2020%20%5Calpha%20%20%3D%20%20%5Cfrac%7B%284000%5Cpi%20-%2030%29%7D%7B3%7D%20%5C%5C%20%20%5Calpha%20%20%3D%20%20%5Cfrac%7B%284000%5Cpi%20-%2030%29%7D%7B60%7D%20)
The percent equation is
n=2.8%×45 or n=0.028×45. where n is the unknown number.
the proportion would be
n/45=2.8/100
the answer is 1.26