All Answers

+130561

OK.....I'll take a stab at this one.

We have, after one year

V = 25000e^(T*N)

Where "V" is the value of the car after T years. We need to find "N"

So, we have (after 1 year)

21250 = 2500e^(1*N)

Divide both sides by 25000

(21250/25000) = e^(1*N)

Now, take the LN of both sides

LN(21250/25000) = LN e^(1*N)

By the property pf logs, the LN e^(1*N) just becomes (1 * N) or just N !!

So we have

LN(21250/25000) = N

Since this is just a messy decimal, let's leave N as it is!!

So, our function is

V = 25000e^(T * LN(21250/25000))

To find the value after 5 years we have

25000e^(5*ln(21250/25000))

About....... $11092.63

I think that's it!!

CPhillMar 20, 2014

+130561

In general, I would agree with Rom's answer..... unless the two points were the endpoints of a diameter.. Only one circle could pass through these, because the midpoint of a line connecting the two points would be the center, and the distance from this midpoint to each of the points would be the same, i.e., the radius. Any other circles passing through the two points would be have to be congruent ones with the same center and radius.

I believe I'm correct on this, but any critique of my logic would be welcome!!!

CPhillMar 20, 2014

+142

5$ = 500cents

500cents / 100 persons

5 cents per person

0.05$.

samgelinasMar 20, 2014

+142

amber6198:
:? The logistic growth function f(t)=67000/1+1339.0e^-0.11t models the numbers of people who have become ill with a particular infection t weeks after its initial outbreak in a particular community. How many people become ill with this infection when the epidemic began?
A) 67,000 people
B) 1340 people
C) 50 people

You only need to replace "t" by "0" in your equation, because "t" it's for the time.

So at the time "0" you'll have 67 000 peoples infected.

samgelinasMar 20, 2014

Thank you

GuestMar 20, 2014

+6252

Quote:
The logistic growth function f(t)=480/1+7.0e^-0.11t describes the population of a species of butterflies months after they are introduced to non-threatening habitat. what is the limiting size of the butterfly population that the habitat will sustain

I think you mean

f(t) = 480/(1+7e ^-0.11t)

To find the limiting size just let t go to infinity

lim{t -> infinity, f(t)} = 480(1 + 0) = 480

RomMar 20, 2014

+6252

Quote:
what is the equation to find a circle on a graph based on a minimum of two points

There are 3 parameters to any circle. It's center coordinate, (x0, y0) and it's radius. There are an infinite number of circles passing through 2 points.

RomMar 20, 2014

+142

CountryGirl333:
Find the height of a triangular prism with a base length of 10 yards, a base height of 20 yards, and a volume of 600 cubic yards.

Volume of a pyramide is V=1/3 * base area * h

600y ³ = 1/3 (10y * 10y) * h

Isolate h

(600y ³ * 3) / 100y ² = h

h = 18yard

To chek if you are right, try to find the volume of the prism.

V = 1/3 * 100 * 18

V = 600 yard ³

samgelinasMar 20, 2014

+118725

riripeti haretuku:
how do I work out percentages

Hi riripeti,

This might be a good place for you to learn from.

http://www.mathsisfun.com/percentage.html

Just highlight the address then right click -> choose 'goto' from the drop down menu.

MelodyMar 20, 2014

+33666

For those not yet comfortable with expanding brackets it is possible the following might help them visualise the process:
expanding.PNG

AlanMar 20, 2014

Find the decimal (for a fraction sipmly dived the number on top by the number on the bottom) and multiply by 100 to get a percent. To find a fraction or decimal from a percentage divide by 100 and then use a graphing calculator to find the fraction

GuestMar 20, 2014

+118725

catgirl123:
x2+x5

Do you mean x ² + x ⁵ ?

You can't simplify this.

x ² and x ⁵ are unlike terms so you can't add them!

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

You could factorise them though, you could take the common factor x ² .

x ² + x ⁵ = x ²(1+x ³)

MelodyMar 20, 2014

+118725

Dalia:
(m-2)^2

You can do this 2 ways

(m-2) ²
=(m-2)(m-2)
=m(m-2) - 2(m-2)
etc

OR
you need to learn quite quickly that
[size=150](a+b) ² = a ² + 2ab + b ²[/size]

so
(m-2) ²
= m ² + 2*m*(-2) + (-2) ²
= m ² - 4m + 4

MelodyMar 20, 2014

+118725

babyy:
m=-1
but how can i get that number?
f(x)=(m+3)x+m-2
f(-2)=-7

Okay Sam,
This is the 3rd post.
f(-2)=(m+3)*-2 +m-2=-7
-2(m+3)+m-2 = -7
-2m-6+m-2 = -7
-m-8 = -7
-m = 1
m=-1
NOW we appear to be in agreement. Thanks Sam.

Babyy, you would have been better off to dump the incorrect thread and start over with a new thread. This caused a LOT of confusion.

MelodyMar 20, 2014

+142

Dalia:
(m-2)^2

Same thing than

(m-2)(m-2)

I'll start you tha answer...

m ² - 2m - ___________________

samgelinasMar 20, 2014

+142

Rom:
Quote:
The sum of two numbers is 85. Twice one number plus four times the other is 218. Determine the numbers.

x + y = 85
2x + 4y = 218

y = 85-x

2x + 4(85-x) = 218
-2x + 340 = 218
-2x = -122
x = 61
y = 85 - x = 85 - 61 = 24