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3 years ago

What is the surface area of the regular pyramid below?

Mathematics

2 answers:

kkurt [141]3 years ago

8 0

Answer:

648 sq units

Step-by-step explanation:

Area of the base= 12×12= 144 sq. units

Perimeter of the base=4×12= 48

Total surface area= 1/2×48×21 + 144

=648 sq units

Vlada [557]3 years ago

5 0

ANSWER

648 square units.

EXPLANATION

The surface area of the regular pyramid is the area of the base plus the area of the 4 triangular faces.

We use the formula;

$S.A = {l}^{2} + 4 \times \frac{1}{2} bh$

where l=12 units is the length of the square base and h=21 units is the vertical height of the triangular faces.

We substitute the values to get;

$S.A = 12^{2} + 4 \times \frac{1}{2} \times 12 \times 21$

$S.A = 144+ 504$

$S.A =648 {units}^{2}$

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Consider the following function. f(x) = |x − 9| Find the derivative from the left at x = 9. If it does not exist, enter NONE. -1

nydimaria [60]

Answer with Step-by-step explanation:

We are given that

$f(x)=\mid x-9\mid$

$f(x)=-(x-9)$ when x<9

$f(x)=x-9$ when $x\geq 9$

LHD

$\lim_{x\rightarrow 9-}f'(x)$

= $-\lim_{x\rightarrow 9-}(x-9)=-1$

RHD

$\lim_{x\rightarrow 9+}f'(x)$

$=\lim_{x\rightarrow 9+}(x-9)=1$

$LHD\neq RHD$

Hence, the function is not differentiable at x=9

8 0

3 years ago

Después de 15 meses de haber prestado un capital al 5% de rédito, tengo que pagar de interés Q468.75. ¿Qué capital se ha prestad

Aleonysh [2.5K]

The capital borrowed, or the principal when the interest was Q468.75 is <u>Q7500</u>.

The principal P, amount borrowed, at a certain rate of interest R%, for a time of T years, giving an interest of I, can be calculated using the formula:

P = (I * 100)/(R * T).

In the question, we are asked to find the capital borrowed, that is, the principal, when the user pays Q468.75 after 15 months at 5% of income.

Thus, Interest (I) = Q468.75, rate of interest (R) = 5%, and time (T) = 15 months = 15/12 years = 1.25 years.

Thus, the principal P, can be calculated by substituting the values in the formula: P = (I * 100)/(R * T).

P = (468.75*100)/(5*1.25),

or, P = 46875/6.25,

or, P = 7500.

Thus, the capital borrowed, or the principal when the interest was Q468.75 is <u>Q7500</u>.

The provided question is in Spanish. The question in English is:

"After 15 months of having borrowed capital at 5% of income, I have to pay Q468.75 in interest. What capital has been borrowed?"

Learn more about Interest at

brainly.com/question/25793394

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2 years ago

7/8, 3/10 whats the common denominator

Ivahew [28]

The common denominator is 40.

3 0

3 years ago

Read 2 more answers

A box is being created out of a 15 inch by 10 inch sheet of metal. Equal-sized squares are cutout of the corners, then the sides

ivolga24 [154]

Answer:

Therefore the dimensions of the square should be 0.1528 inch by 0.1528 inch so, the box has largest volume.

Step-by-step explanation:

Given that,

A box is being created out of a 15 inches by 10 inches sheet of metal.

The length of the one side of the squares which are cut out of the each corners of the metal sheet be x.

The length of the metal box be = (15-2x) inches.

The width of the metal box be =(10-2x) inches

The height of the metal box be =x inches

Then, the volume of the metal box= length×width×height

=(15-2x)(10-2x)x cubic inches

=(150x-50x²+4x³) cubic inches

∴ V= 4x³-50x²+15x

Differentiating with respect to x

V'=12x²-100x+15

Again differentiating with respect to x

V''=24x-100

For maximum or minimum value, V'=0

12x²-100x+15=0

Apply quadratic formula $x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$ , here a=12, b= -100 and c=15

$x=\frac{-(-100)\pm\sqrt{(-100)^2-4.12.15}}{2.12}$

$\Rightarrow x=\frac{100\pm\sqrt{9280}}{2.12}$

$\Rightarrow x=0.1528,8.18$

For x= 8.18, The value of (15-2x) and (10-2x) will negative.

∴x=0.1528 .

Now, $V''|_{x=0.1528}=24(0.1528)-100$

∴At x=0.1528 inch, the volume of the metal box will be maximum.

Therefore the dimensions of the square should be 0.1528 inch by 0.1528 inch so, the box has largest volume.

4 0

4 years ago

In a class of strength 60, 75% like to become teachers. how manu dont like to be teachers?

timurjin [86]

No. of people don't like to be teacher

= 100% - 75% = 25%

<h3> $\frac{25}{100} \times 60 \\ = 15$ </h3>

So, 15 number of students doesn't like to be teacher

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3 years ago