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2 years ago

Find the value of f(-1) for the function below

Mathematics

1 answer:

mrs_skeptik [129]2 years ago

8 0

Put the value of x = -1 to the equation of a function f(x):

$f(x)=\dfrac{2}{3}\times3^{3x+12}\\\\f(-1)=\dfrac{2}{3}\times3^{3(-1)+12}=\dfrac{2}{3}\times3^{-3+12}=\dfrac{2}{3}\times3^9=\dfrac{2}{1}\times3^8=13,122\to\boxed{B.}$

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Thomas needs to buy a cardboard sheet that will allow him to make his 224 in 3 box. To help construct the box, he decided to cut

Slav-nsk [51]

Answer:

Part 1; The volume of the box Thomas wants to make is 224 = 2·w² + 12·w

Part 2; The zeros for the equation of the function, are w = -14, or w = 8

Part 3

The width of the box is 8 inch

The length of the box, is 14 inches

The height of the box, is given as 2 inches

Part 4

Please find attached the graph of the function

Step-by-step explanation:

Part 1

The volume of the box Thomas wants to make, V = 224 in.³

The dimensions he cuts out from the length and width = 2 in² each

The length of the box = 6 inches + The width of the box

Let <em>l</em> represent the length of the box and let <em>w</em> represent the width of the box, we have;

l = 6 + w

The height of the box, h = The length of the cut out square = 2 inches

The volume of the box, V = Length, l × Width, w × Height, h

∴ V = l × w × h

l = 6 + w, h = 2

∴ V = (6 + w) × w × 2

V = 2·w² + 12·w,

The equation of the volume of the box, V = 2·w² + 12·w, where, V = 224

∴ 224 = 2·w² + 12·w

Part 2

The zeros of the equation for the volume of the box, V = 2·w² + 12·w, where, V = 224 are found as follows;

V = 224 = 2·w² + 12·w

∴ 2·w² + 12·w - 224 = 0

Dividing by 2 gives;

(2·w² + 12·w - 224)/2 = w² + 6·w - 112 = 0

∴ (w + 14) × (w - 8) = 0

The zeros for the equation of the function, are w = -14, or w = 8

Part 3

We reject the value, w = -14, therefore, the width of the box, w = 8 inch

The length of the box, l = 6 + w

∴ l = 6 + 8 = 14

The length of the box, l = 8 inches

The height of the box, <em>h</em>, is given as h = 2 inches

Part 4

The graph of the function created with MS Excel is attached

4 0

2 years ago

Factor each. <br><br> 5x to the 3rd ppwer + 25x to the 2nd power -4x -20 = 0

lesya692 [45]

If you are looking forward to adding them together you will get 145. Just need to know if this questions had options?

4 0

2 years ago

Can someone help me

jeka57 [31]

OK SURE WHAT IS IT? SO I CAN ANSWER YOUR QUEST.?

5 0

2 years ago

Hello! How do I find the surface area of this prism? Thanks!

Studentka2010 [4]

Answer: Choice C) 124 square cm

------------------------------------------------------------------

Explanation:

Let's calculate the area of the trapezoid shown
b1 and b2 are the parallel bases; h is the height of the 2D trapezoid
b1 = 2
b2 = 5
h = 1.5

A = h*(b1+b2)/2
A = 1.5*(2+5)/2
A = 1.5*7/2
A = 10.5/2
A = 5.25
The area of one 2D trapezoid is 5.25 sq cm
There are two of these trapezoids that form the base faces of the trapezoidal prism. So the total base area is 2*5.25 = 10.5 sq cm
Keep this value (10.5) in mind. We'll use it later.

------------

Now onto the lateral surface area (LSA)
It turns out that the formula for the LSA is
LSA = p*d
where
p = perimeter of the trapezoid shown
d = depth or height of the 3D trapezoid (I'm not using h as it was used earlier)
This formula works for any polygonal base. It doesn't have to be a trapezoid.

In this case the perimeter is,
p = 1.7+2+2.65+5
p = 11.35

So
LSA = p*d
LSA = 11.35*10
LSA = 113.5

Add this LSA to the base area found earlier
10.5+113.5 = 124

The total surface area is 124 square cm

8 0

2 years ago

Solve: -rt - 80 > 30 for r. show your work!

vaieri [72.5K]

<h2>Steps:</h2>

So to solve for a variable, we must isolate it onto 1 side of the inequality. In this case, we must isolate r. Firstly, add 80 to both sides of the inequality:

$-rt>110$

Next, divide both sides by t:

$-r>\frac{110}{t}$

Next, multiply both sides by -1. Since we are multiplying by a <em>negative</em> number, flip the inequality symbol as well:

$r$

<h2>Answer:</h2>

<u>In short, your final answer is $r$ </u>

7 0

2 years ago