If the surface area of a cylinder is given by SA =

Mathematics

1 answer:

Mars2501 [29]2 years ago

7 0

Answer:

The height is 11/2

Step-by-step explanation:

We know SA = 30n

and r = 2

We are solving for h. So plug in our values

30n = 2n(2)^2 + 2n(2)h

Multiply and square on the right side terms

30n = 8n + 4nh

Divide everything by n

30 = 8 + 4h

Subtract 8 on both sides

22 = 4h

Divide by 4 on both sides

h = 22/4 = 11/2

Check:

30n = 2n(2)^2 + 2n(2)(11/2)

30n = 8n + 22n

30n = 30n

You might be interested in

Estimate the integral ∫6,0 x^2dx by the midpoint estimate, n = 6

Anettt [7]

Splitting up the interval [0, 6] into 6 subintervals means we have

$[0,1]\cup[1,2]\cup[2,3]\cup\cdots\cup[5,6]$

and the respective midpoints are $\dfrac12,\dfrac32,\dfrac52,\ldots,\dfrac{11}2$ . We can write these sequentially as ${x_i}^*=\dfrac{2i+1}2$ where $0\le i\le5$ .

So the integral is approximately

$\displaystyle\int_0^6x^2\,\mathrm dx\approx\sum_{i=0}^5({x_i}^*)^2\Delta x_i=\frac{6-0}6\sum_{i=0}^5({x_i}^*)^2=\sum_{i=0}^5\left(\frac{2i+1}2\right)^2$

Recall that

$\displaystyle\sum_{i=1}^ni^2=\frac{n(n+1)(2n+1)}6$
$\displaystyle\sum_{i=1}^ni=\frac{n(n+1)}2$
$\displaystyle\sum_{i=1}^n1=n$

so our sum becomes

$\displaystyle\sum_{i=0}^5\left(\frac{2i+1}2\right)^2=\sum_{i=0}^5\left(i^2+i+\frac14\right)$
$=\displaystyle\frac{5(6)(11)}6+\frac{5(6)}2+\frac54=\frac{143}2$

8 0

2 years ago

What is thirty divided by ten

ivanzaharov [21]

Answer:

It is three.................

3 0

2 years ago

Read 2 more answers

A coin is tossed, and a die is rolled. Find the probability of getting heads and then rolling a 6.

Colt1911 [192]

Answer: