2. Barnes and Noble bookstore is having a sale. Dr. Mumin's book sells for

The circumference of a circle is about 37.7 cm and the diameter is about 12 cm. What expression best represents the value of π ?

Yakvenalex [24]

Answer:

Step-by-step explanation:

Circumference of a circle means the perimeter of a circle and it is given be

Perimeter=2πr

P=2πr

Though π is a constant

But this question want us to find π

Make π the subject of the formula

Then, divide both side by

π=P/2r

Given that P=37.7cm

And diameter =12

And radius is half of diameter.

Therefore, radius =12/2=6cm

Then

π=P/2r

π=37.7/2×6

π=37.7/12.

Then, the last option is the correct option

6 0

3 years ago

Which expression represents the number 2i4−5i3+3i2+−81‾‾‾‾√ rewritten in a+bi form?

vichka [17]

Answer:

The expression $-1+14i$ represents the number $2i^4-5i^3+3i^2+\sqrt{-81}$ rewritten in a+bi form.

Step-by-step explanation:

The value of $i$ is $i=\sqrt{-1}[tex] or [tex]i^{2}=-1[\tex].Now [tex]i^{4}$ in term of $i^{2}[\tex] can be written as, [tex]i^{4}=i^{2}\times i^{2}$

Substituting the value,

$i^{4}=\left(-1\right)\times \left(-1\right)$

Product of two negative numbers is always positive.

$\therefore i^{4}=1$

Now $i^{3}$ in term of $i^{2}[\tex] can be written as, [tex]i^{3}=i^{2}\times i$

Substituting the value,

$i^{3}=\left(-1\right)\times i$

Product of one negative and one positive numbers is always negative.

$\therefore i^{3}=-i$

Now $\sqrt{-81}$ can be written as follows,

$\sqrt{-81}=\sqrt{\left(81\right)\times\left(-1\right)}$

Applying radical multiplication rule,

$\sqrt{ab}={\sqrt{a}}\sqrt{b}$

$\sqrt{\left(81\right)\times\left(-1\right)}={\sqrt{81}}\sqrt{-1}$

Now, $\sqrt{\left(81\right)=9$ and $\sqrt{-1}}=i$

$\therefore \sqrt{\left(81\right)\times\left(-1\right)}=9i$

Now substituting the above values in given expression,

$2i^4-5i^3+3i^2+\sqrt{-81}=2\left(1\right)-5\left(-i\right)+3\left(-1\right)+9i$

Simplifying,

$2+5i-3+9i$

Collecting similar terms,

$2-3+5i+9i$

Combining similar terms,

$-1+14i$

The above expression is in the form of a+bi which is the required expression.

Hence, option number 4 is correct.

5 0

3 years ago

2,652 divided by 48.

kozerog [31]

48 goes in to 2,652 how many times...that your answer...48 cannot go into 2 6 or 5 but it can into 265 5 times which equal240 subtract that from265 =25 ,48 cannot go in to 25 so bring down the 2 to make it 252 then divide 48 by 252 which goes 5 times equaling12 48 cannot go in to 12 so add a 0 to 2652 to make it 26520 then bring the 0 down to make 12 120 then divide 48 into that which it goes 2 times equaling 96 120subtract 96=24 48 cannot go into 24 so add another 0 to 26520 to make it 265200 bring down the zero to make 24 into 240 divide 48 into that which gives you240 subtract 240 from 240 = 0 so your answer is 48 divide into 2652=525

7 0

3 years ago

Type your number answer in decimal form. do not round . ? millimeters = 9.2 cenimeters

adell [148]

Answer:

10 centimeter=92 milimeter

Step-by-step explanation:

we know that

one centimeter contains 10 milimeter or

1 centimeter is equal to 10 milimeter

1 centimeter=10 milimeter

we have to find

how many milimetersare there in 9.2 milimeters

9.2 centimeter=? milimeter

for this we will multiply by 9.2 on both sides

1 centimeter=10 milimeter

9.2 centimeter=10*(9.2)=92 milimeter

10 centimeter=92 milimeter

3 0

3 years ago

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What does the 6 stand for in 8,375,693.1? 0.6 6 600 6000

Blababa [14]

Answer:

6 stand for 600(six hundred).

8 0

3 years ago

Read 2 more answers