All categories

3 years ago

Find the lateral surface area of this

Mathematics

1 answer:

Jobisdone [24]3 years ago

7 0

Answer:

22/7×9×3=22×9×3=594÷7=84.85

You might be interested in

Find the slope (2,5) and (6,2)

Drupady [299]

Answer:

slope =-3

Step-by-step explanation:

slope = y2 - y1

x2 - x1

=2 - 5

6 - 2

= -3

5 0

2 years ago

The plane that passes through the point (-2,2,0) and contains the line with symmetric equations x=y=2z

ehidna [41]

Answer:

I want to help you but I'm trying to sign into to brainy and I have to answer someone, sorry for being a noucance

3 0

2 years ago

Prove or disprove (from i=0 to n) sum([2i]^4) <= (4n)^4. If true use induction, else give the smallest value of n that it doe

ddd [48]

Answer:

The statement is true for every n between 0 and 77 and it is false for $n\geq 78$

Step-by-step explanation:

First, observe that, for n=0 and n=1 the statement is true:

For n=0: $\sum^{n}_{i=0} (2i)^4=0 \leq 0=(4n)^4$

For n=1: $\sum^{n}_{i=0} (2i)^4=16 \leq 256=(4n)^4$

From this point we will assume that $n\geq 2$

As we can see, $\sum^{n}_{i=0} (2i)^4=\sum^{n}_{i=0} 16i^4=16\sum^{n}_{i=0} i^4$ and $(4n)^4=256n^4$ . Then,

$\sum^{n}_{i=0} (2i)^4 \leq(4n)^4 \iff \sum^{n}_{i=0} i^4 \leq 16n^4$

Now, we will use the formula for the sum of the first 4th powers:

$\sum^{n}_{i=0} i^4=\frac{n^5}{5} +\frac{n^4}{2} +\frac{n^3}{3}-\frac{n}{30}=\frac{6n^5+15n^4+10n^3-n}{30}$

Therefore:

$\sum^{n}_{i=0} i^4 \leq 16n^4 \iff \frac{6n^5+15n^4+10n^3-n}{30} \leq 16n^4 \\\\ \iff 6n^5+10n^3-n \leq 465n^4 \iff 465n^4-6n^5-10n^3+n\geq 0$

and, because $n \geq 0$ ,

$465n^4-6n^5-10n^3+n\geq 0 \iff n(465n^3-6n^4-10n^2+1)\geq 0 \\\iff 465n^3-6n^4-10n^2+1\geq 0 \iff 465n^3-6n^4-10n^2\geq -1\\\iff n^2(465n-6n^2-10)\geq -1$

Observe that, because $n \geq 2$ and is an integer,

$n^2(465n-6n^2-10)\geq -1 \iff 465n-6n^2-10 \geq 0 \iff n(465-6n) \geq 10\\\iff 465-6n \geq 0 \iff n \leq \frac{465}{6}=\frac{155}{2}=77.5$

In concusion, the statement is true if and only if n is a non negative integer such that $n\leq 77$

So, 78 is the smallest value of n that does not satisfy the inequality.

Note: If you compute $(4n)^4- \sum^{n}_{i=0} (2i)^4$ for 77 and 78 you will obtain:

$(4n)^4- \sum^{n}_{i=0} (2i)^4=53810064$

$(4n)^4- \sum^{n}_{i=0} (2i)^4=-61754992$

7 0

3 years ago

Which of the following ordered pairs is a solution of the function f(x)=3x-1

Lemur [1.5K]

The answer is (-1,-4)

7 0

3 years ago

The area of a triangular flower bed in the park has an area of

blagie [28]

Answer:

b = 24 ft

h = 10 ft

Step-by-step explanation:

120 = ½hb

120 = ½h(3h - 6)

240 = h(3h - 6)

240 = 3h² - 6h

80 = h² - 2h

0 = h² - 2h - 80

0 = (h - 10)(h + 8)

h = 10 ft or -8 ft

we ignore -8 as it makes no sense for a triangle side length.

b = 3(10) - 6 = 24 ft

8 0

2 years ago