The midpoint of XY is -0.5
You will need 6 tennis balls a
By inspection, it's clear that the sequence must converge to

because

when

is arbitrarily large.
Now, for the limit as

to be equal to

is to say that for any

, there exists some

such that whenever

, it follows that

From this inequality, we get




As we're considering

, we can omit the first inequality.
We can then see that choosing

will guarantee the condition for the limit to exist. We take the ceiling (least integer larger than the given bound) just so that

.
They always say to do the problem in parentheses first
Plot the points on a graph. Connect the dots into a triangle. See that the height of the triangle is from y=5 down to y=1. So the height is 4 units.
Area of a triangle: A = (1/2)BH
You need to find the length of the base. Which is from point (-4,1) to (0,1). You can use the distance formula r just see from the graph that the base is 4 units.
A = (1/2)(4)(4)
A = 8
** Distance formula fyi
d² = (X-x)² + (Y-y)²
with points (X,Y) and (x,y)
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