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3 years ago

14

What's the length of BD and how?

1 answer:

Advocard [28]3 years ago

7 0

I believe it is 4 or 5

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Please help answer the question in the picture

musickatia [10]

A in the answer for this question
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3 years ago

Read 2 more answers

A solid has faces that consist of 1 pentagon, 5 congruent equilateral triangles, and 5 congruent squares. The solid has 11 verti

mrs_skeptik [129]

So the solid consist of 1 pentagon, 5 congruent equilateral triangle and 5 congruent squares and has 11 vertices so the number of edges of this solid is 20. I hope you are satisfied with my answer and feel free to ask form more if you have more clarifications.

5 0

3 years ago

Q. If A is a square matrix such that A² = A, then write the value of 7 A −(I + A)³, where I is an identity matrix.

andriy [413]

Answer:

7A−(I + A)³

=7A−(1³ + A³ +3.I.A² +3.1².A)

=7A−(I+ A².A+3A² +34)

= 7A-(I+A.A+3A+34) (*: A² = A)

=7A-(I+ A² +6A)

= 7A-(I+A+64)

=7A-(1+7A)

=7A-I-7A

=-1

6 0

2 years ago

Oil is pumped continuously from a well at a rate proportional to the amount of oil left in the well. Initially there were millio

JulijaS [17]

Answer:

The amount of oil was decreasing at 69300 barrels, yearly

Step-by-step explanation:

Given

$Initial =1\ million$

$6\ years\ later = 500,000$

Required

At what rate did oil decrease when 600000 barrels remain

To do this, we make use of the following notations

t = Time

A = Amount left in the well

So:

$\frac{dA}{dt} = kA$

Where k represents the constant of proportionality

$\frac{dA}{dt} = kA$

Multiply both sides by dt/A

$\frac{dA}{dt} * \frac{dt}{A} = kA * \frac{dt}{A}$

$\frac{dA}{A} = k\ dt$

Integrate both sides

$\int\ {\frac{dA}{A} = \int\ {k\ dt}$

$ln\ A = kt + lnC$

Make A, the subject

$A = Ce^{kt}$

$t = 0\ when\ A =1\ million$ i.e. At initial

So, we have:

$A = Ce^{kt}$

$1000000 = Ce^{k*0}$

$1000000 = Ce^{0}$

$1000000 = C*1$

$1000000 = C$

$C =1000000$

Substitute $C =1000000$ in $A = Ce^{kt}$

$A = 1000000e^{kt}$

To solve for k;

$6\ years\ later = 500,000$

i.e.

$t = 6\ A = 500000$

So:

$500000= 1000000e^{k*6}$

Divide both sides by 1000000

$0.5= e^{k*6}$

Take natural logarithm (ln) of both sides

$ln(0.5) = ln(e^{k*6})$

$ln(0.5) = k*6$

Solve for k

$k = \frac{ln(0.5)}{6}$

$k = \frac{-0.693}{6}$

$k = -0.1155$

Recall that:

$\frac{dA}{dt} = kA$

Where

$\frac{dA}{dt}$ = Rate

So, when

$A = 600000$

The rate is:

$\frac{dA}{dt} = -0.1155 * 600000$

$\frac{dA}{dt} = -69300$

<em>Hence, the amount of oil was decreasing at 69300 barrels, yearly</em>

7 0

2 years ago

an energy drink company claims that it’s produced inscreases students memory levels. to support its claims, the company issues a

Alenkasestr [34]

Boba all the way, it is delicious and I can't live without it

5 0

3 years ago