A conical cup is made from a circular piece of paper with radius 4 cm by cutting out a sector and joining the edges as shown bel
ow. Suppose θ = 3π/2.Find the volume V of the cup.
1 answer:
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Answer:
see attached
Step-by-step explanation:
I find it convenient to let a graphing calculator draw the graph (attached).
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If you're drawing the graph by hand, there are a couple of strategies that can be useful.
The first equation is almost in slope-intercept form. Dividing it by 2 will put it in that form:
y = 2x -4
This tells you that the y-intercept, (0, -4) is a point on the graph, as is the point that is up 2 and right 1 from there: (1, -2). A line through those points completes the graph.
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The second equation is in standard form, so the x- and y-intercepts are easily found. One way to do that is to divide by the constant on the right to get ...
x/2 +y/3 = 1
The denominators of the x-term and the y-term are the x-intercept and the y-intercept, respectively. If that is too mind-bending, you can simply set x=0 to find the y-intercept:
0 +2y = 6
y = 6/2 = 3
and set y=0 to find the x-intercept
3x +0 = 6
x = 6/3 = 2
Plot the intercepts and draw the line through them for the graph of this equation.
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Here, we have suggested graphing strategies that don't involve a lot of manipulation of the equations. The idea is to get there as quickly as possible with a minimum of mistakes.
Answer:
The interest rate is 7.58%
Step-by-step explanation:
Compound continuous interest can be calculated using the formula:
A = P, where
- A is the future value of the investment, including interest
- P is the principal investment amount (the initial amount)
- r is the interest rate in decimal
- t is the time the money is invested for
∵ Angus has $3,000 he want to invest
∴ P = 3000
∵ The interest rate is compounded continuously
∵ Angus has $5,500 in 8 years
∴ A = 5500
∴ t = 8
→ Substitute them in the rule above to find r
∵ 5500 = 3000
→ Divide both sides by 3000
∴ =
→ Insert ㏑ in both sides
∵ ㏑( ) = ㏑(
)
→ Remember ㏑() = n
∴ ㏑( ) = 8r
→ Divide both sides by 8
∴ 0.07576697545 = r
→ Multiply it by 100% to change it to a percentage
∴ r = 0.07576697545 × 100%
∴ r = 7.576697545 %
→ Round it to the nearest hundredth
∴ r ≅ 7.58
∴ The interest rate is 7.58%