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2 years ago

7

A right rectangular pyramid is sliced horizontally (across) at the red line by a plane parallel to the base. What is the shape o

f the cross-section?

1 answer:

Alex17521 [72]2 years ago

7 0

It’s D!!! Pyramid pls give brainliest it can’t be triangle cause triangles r 2D and pyramids are 3R

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What is the percent of increase from 106 miles to 122 miles?

Elis [28]

Answer:

15.094 %

Step-by-step explanation:

[(122 - 106) /106] 100

(16/106) 100

(0.15094)x100

15.094

8 0

3 years ago

If you are offered one slice from a round pizza (in other words, a sector of a circle) and the slice must have a perimeter of 24

VARVARA [1.3K]

Answer:

A 12 in diameter will reward you with the largest slice of pizza.

Step-by-step explanation:

Let $r$ be the radius and $\theta$ be the angle of a circle.

According with the graph, the area of the sector is given by

$A=\frac{1}{2}r^2\theta$

The arc lenght of a circle with radius $r$ and angle $\theta$ is $r \theta$

The perimeter of the pizza slice is composed of two straight pieces, each of length r inches, and an arc of the circle which you know has length s = rθ inches. Thus the perimeter has length

$2r+r\theta=24 \:in$

We need to express the area as a function of one variable, to do this we use the above equation and we solve for $\theta$

$2r+r\theta=24\\r\theta=24-2r\\\theta=\frac{24-2r}{r}$

Next, we substitute this equation into the area equation

$A=\frac{1}{2}r^2(\frac{24-2r}{r})\\A=\frac{1}{2}r(24-2r)\\A=12r-r^2$

The domain of the area is

$0$

To find the diameter of pizza that will reward you with the largest slice you need to find the derivative of the area and set it equal to zero to find the critical points.

$\frac{d}{dr} A=\frac{d}{dr}(12r-r^2)\\A'(r)=\frac{d}{dr}(12r)-\frac{d}{dr}(r^2)\\A'(r)=12-2r$

$12-2r=0\\-2r=-12\\\frac{-2r}{-2}=\frac{-12}{-2}\\r=6$

To check if $r=6$ is a maximum we use the Second Derivative test

if $f'(c)=0$ and $f''(c)$ , then f(x) has a local maximum at x = c.

The second derivative is

$\frac{d}{dr} A'(r)=\frac{d}{dr} (12-2r)\\A''(r)=-2$

Because $A''(r)=-2$ the largest slice is when r = 6 in.

The diameter of the pizza is given by

$D=2r=2\cdot 6=12 \:in$

A 12 in diameter will reward you with the largest slice of pizza.

3 0

3 years ago

Divide the difference of 18 and 3 by the sun of 1 and 2

NikAS [45]

Okay.

(18-3)/(1+2) = 15/3 = 5

answer: 5

4 0

4 years ago

Read 2 more answers

Need answers for 70-75

adoni [48]

Answer:

70. 0

71. -54

72. 12

73. 86

74. 59

Step-by-step explanation:

To evaluate an expression, substitute specific values for the variables and simplify using Order of Operations.

70. c-3d becomes

$(1)-3(\frac{1}{3}) = 1-(\frac{3}{3}) = 1-1 = 0$

71. $x+x^3-4x^4$ becomes

$2+2^3-4(2)^4 = 2+8-4(16) = 2+8-64=10-64=-54$

72. $5a+3a^2$ becomes

$5(-3)+3(-3)^2 = -15 +3(9) = -15 + 27 = 12$

73. $F=\frac{9}{5}C+32$ becomes

$F=\frac{9}{5}(30)+32=\frac{270}{5}+32 = 54+32 = 86$

74. $F=\frac{9}{5}C+32$ becomes

$F=\frac{9}{5}(15)+32=\frac{135}{5}+32 = 27+32 = 59$

8 0

3 years ago

Please help matimatik 10 points

Liono4ka [1.6K]

Answer:

0.03

Step-by-step explanation:

Hope I helped

-Hunter Cross

Please mark Brainliest if Correct

6 0

3 years ago