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:
5)102,78
6)56,56
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Use desmos graphing calculator, for visuals. It's easy to use as well.
A is 0 (zero)
(1x1 + 2x1 - 3)
B) D ( lies on 1 on our x-axis)
C) This tells you to draw a line at zero on the y-axis, a horizontal line BTW & read off the x values, where the line touches the pink graph/diagram.
y=x^2+2x-3 is the similar to x^2+2x-3=0 because the letter y now represents zero. So, that's why we draw the line y=0 (a horizontal line at zero). Then, use it to find the x values.
Thus, x = - 3 & x = 1
Hope this helps!
Answer:

Step-by-step explanation:
see the attached figure to better understand the problem
In the right triangle ABC
Applying the Pythagorean Theorem

substitute the given values

solve for BC



Answers:
☆☆☆☆☆☆☆☆aTriangle ZYX
bTriangle YZX
cTriangle XZY
dTriangle XYZ