Looks like you just evaluated the summand for the given value of

, whereas the question is asking you to find the value of the sum for the first

terms.
Let

. Then

is the

th partial sum.

happens to be the first term in the series, which is why that box is marked correct:

But the next partial sum is not correct:

and this is not the same notion as the second term (which indeed is 0.75) in the series.
I see your last line is : c(x) = 0.9(x^2-10)^2 + 101.1
Let y = x^2, then c(y) = 0.9(y-10)^2 + 101.1
Apparently, c(y) is a parabola, min is 101.1 when y = 10, max is infinity
So let x^2 = 10 -> x = sqrt(10) or -sqrt(10), min is 101.1, max is infinity
I got D for the answer pi x 12mmsquare cause you're only measuring the area of the bullseye and i got 452.39
Answer:
The value of x is the value where the line crosses the x-axis!
________________________________________________________
Hope this helps!!
Please tell me if I have made a mistake!!
I enjoy learning from them:)
Simplify both sides of the equation
x/16−(x+2/8) = 2x/16 + −1/8x + −1/4 = 2
Distribute
1/16x + −1/8x + −1/4 = 2
(1/16x + −1/8x)+(−1/4) = 2
Combine Like Terms
−1/16x + −1/4 = 2
Add 1/4 to both sides.
−1/16x + −1/4 + 1/4 = 2 + 1/4
−1/16x = 9/4
Multiply both sides by 16/(-1).
(16/−1)*(−1/16x)=(16/−1)*(9/4)
x=−36