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3 years ago

Plz someone help me I just guessed but what's the real answer, I need this asap

Mathematics

1 answer:

sladkih [1.3K]3 years ago

6 0

Answer: Honestly it has to be B dont see how the others come into play

Step-by-step explanation:

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jessie has a peice of wood that is 8 feet long he needs to cut pieces that are 7/8 of a foot long how many pieces will he be abl

attashe74 [19]

Answer: 9 pieces

Explanation: Divide 8 by 7/8 to find the number of cut pieces and you'll get 9.

3 0

3 years ago

The circumference of a sphere was measured to be 80 cm with a possible error of 0.5 cm. A) Use differentials to estimate the max

siniylev [52]

Answer:

A) The maximum error in the calculated surface area: $25cm^2$

Relative error: $0.013$

B) The maximum error in the calculated volume: $162cm^2$

Relative error: $0.019$

Step-by-step explanation:

A) The formula for the surface area is:

$A=4\pi r^2$

The measured value is the circumference which is equal to:

$C=2\pi r$

then the radius is:

$r=\frac{C}{2\pi}$

Substituting in the formula of the surface:

$A=4\pi(\frac{C}{2\pi})^2\\A=4\pi(\frac{C^2}{4\pi^2})\\A=\frac{C^2}{\pi}$

Using the formula to calculate the error:

$dy=f'(x)dx$

Where $x$ is the variable measured and $y$ is a function of $x$ ( $y=f(x)$ ).

$dA=f'(C)dC\\dA=\frac{2C^{(2-1)}}{\pi}dC\\dA=\frac{2C}{\pi}dC$

We have C=80cm and dC=0.5cm

$dA=\frac{2C}{\pi}dC\\dA=\frac{2(80)}{\pi}(0.5)\\dA=\frac{160}{\pi}(0.5)\\dA=50.9296(0.5)\\dA=25.4648\approx25cm^2$

The relative error is the maximum error divide by the total area. The total area is: $A=\frac{C^2}{\pi}=\frac{(80)^2}{\pi}=\frac{6400}{\pi}=2037.1833cm^2$

$\frac{dA}{A}=\frac{25.4648}{2037.1833} =0.0125\approx0.013$

B) The formula for the volume is:

$V=\frac{4}{3} \pi r^3$

Using $r=\frac{C}{2\pi}$

$V=\frac{4}{3} \pi r^3\\V=\frac{4}{3} \pi (\frac{C}{2\pi})^3\\V=\frac{4}{3} \pi (\frac{C^3}{8\pi^3})\\V=\frac{1}{3}(\frac{C^3}{2\pi^2})\\V=\frac{C^3}{6\pi^2}$

The maximum error is:

$dV=\frac{3C^{3-1}}{6\pi^2}dC\\dV=\frac{C^{2}}{2\pi^2}dC\\dV=\frac{(80)^{2}}{2\pi^2}(0.5)\\dV=\frac{6400}{2\pi^2}(0.5)\\dV=\frac{6400}{2\pi^2}(0.5)\\dV=(324.2278)(0.5)\\dV=162.1139\approx162cm^2$

The calculated volume is:

$V=\frac{C^3}{6\pi^2}\\V=\frac{(80)^3}{6\pi^2}\\V=\frac{512000}{6\pi^2}\\V=8646.0743$

The relative error is:

$\frac{dV}{V}=\frac{162.1139}{8646.0743}=0.0188\approx0.019$

3 0

3 years ago

F(x) = square root x-3

aleksandrvk [35]

I think the answer is c

7 0

3 years ago

Andrew is two years older than Beatrice, and Chris is three years younger than Beatrice. The product of Andrew's age and Chris'

stich3 [128]

Answer:

Step-by-step explanation:

A = B + 2

C = B - 3

A x C = 66

A = Andrew

C = Chris

B = Beatrice

Multiply A and c together

(B + 2) x (b - 3)

b^2 - 3b + 2b - 6

b^2 -b - 6 = 66

b^2 - b - 72 = 0

factors of -72b^2 that add up to - b are -9b + 8b

b^2 + 8b -9b - 72

b (b + 8) -9(b + 8)

b = 9 or - 8

b = 9

5 0

3 years ago

If it was a snow day what would you do?

Olegator [25]

Answer:

Probably play video games and drink hot chocolate. Maybe go sledding to.

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

Plz someone help me I just guessed but what's the real answer, I need this asap​

Plz someone help me I just guessed but what's the real answer, I need this asap