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3 years ago

WILL GIVE 20 POINTS

Mathematics

1 answer:

Oksanka [162]3 years ago

3 0

Answer:

The answer is B

Step-by-step explanation:

75 + x = 90

First, Virginia had to write an equation to solve for x.

75 - 75 + x = 90 - 75

Second, Virginia used the subtraction property of equality to isolate x.

x = 15

Third, "x = 15" was the answer Virginia got after subtracting 90 and 75.

75 + 15 = 90

Finally, she had to verify her answer

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area = 1/2 x h x b

14*9 = 126

126/2 = 63 square inches

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What is the best estimate of 11 1/5÷2 3/4

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Answer:4

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Use the graph that shows the solution to

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Answer:

The solution for f(x) = g(x) are;

x = 1 and x = -1

Step-by-step explanation:

The given equations for the functions, g(x) are;

$f(x) = \dfrac{1 + 2\cdot x}{x}$

g(x) = 2 + x

The solution for f(x) = g(x), is given by equating the equations of the two functions as follows;

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$\dfrac{1 + 2\cdot x}{x} = 2 + x$

By cross multiplication, we have;

1 + 2·x = x × (2 + x) = 2·x + x²

∴ x² + 2·x - 2·x - 1 = 0

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(x - 1)·(x + 1) = 0

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2 years ago

Surface area of a box dimensions of 16 18 and 14

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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:

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

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3 years ago