Math Is Fun Forum

ln(x) means the "natural logarithm of x" and can also be represented as log[sub]e[/sub](x). The natural logarithm of a number x is the power to which e would have to be raised to equal x.

However, normally to find a solution to something you first need an equation (something with an equals sign), like ln(x) = 0 or ln(4x) = 2.

Perhaps in you could try looking here:

http://www.mathsisfun.com/algebra/logarithms.html

If all that makes sense scroll down to 'Natural Logarithms: Base "e"'

I got 79 but had no cones, only cylinders. Was I playing the same game as you guys?

I'm most likely doing something wrong, but I when I click 'Join' I get a fatal error ...

Fatal error: Cannot redeclare ...

If you think of this problem visually, you are trying to find the points on a graph where a hyperbola and a circle intersect.

1 -- (x+5)² +(y+2)²=169
2 -- xy - 21=0

xy - 21 = 0
xy = 21
y = 21/x

substitute y = 21/x into equation 1:
(x+5)² +(21/x+2)²=169

and expand:
x² + 10x + 25 + 441/(x²) + 84/x + 4 = 169

which gives:
x^4 + 10x³ - 140x² + 84x + 441 = 0
(x - 7)(x³ + 17x² - 21x - 63) = 0

solve for x:
∴ x ≈ -17.9734 or x ≈ -1.44775 or x ≈ 2.42112 or x = 7

Arnie gets 50 yards, and Susan 25.

16 yards * 5 students = 75 yards

75 yards = arnie + susan, and
arnie = 2 x susan

so,
75 = 3 x susan
susan = 25 yards

75 - 25 = arnie = 50 yards.

edit - oh, good point. i can't multiply./

No.

OMGGGG LYK LOOK WHO IT IS!!!!!!!!!!!11

1. Man, alive.
2. No, he's not a sportsperson.
3. No, he's not a cinema/television star.
4. No, he's not a politician.
5. Yes, his family name does start with a letter between A-L.
6. Yes, he was born before 1970.
7. Yes, he hails from the A continents.
8. No, he is not Asian.
9. No, he is not a writer*.
10. No, his family name does not start with a letter between A-G.
11. No, he is not a doctor.
12. No, he is not a scientist/mathematician.
13. Yes, from USA.
14. No, not a painter.
      No, not Australian ... [we can omit this]
15. Yes, a musician.
16. No, not Brodie Foster Hubbard.

1. Man, alive.
2. No, he's not a sportsperson.
3. No, he's not a cinema/television star.
4. No, he's not a politician.
5. Yes, his family name does start with a letter between A-L.
6. Yes, he was born before 1970.
7. Yes, he hails from the A continents.
8. No, he is not Asian.
9. No, he is not a writer*.
10. No, his family name does not start with a letter between A-G.
11. No, he is not a doctor.
12. No, he is not a scientist/mathematician.
13. Yes, from USA.
14.  No, not a painter.
15. No, not Australian ...

1. Man, alive.
2. No, he's not a sportsperson.
3. No, he's not a cinema/television star.
4. No, he's not a politician.
5. Yes, his family name does start with a letter between A-L.
6. Yes, he was born before 1970.
7. Yes, he hails from the A continents.
8. Um ... I don't actually know. Hang on, I'll see if I can find out.

1. Man, alive.
2. No, he's not a sportsperson.

Play against a computer ...
http://www.20q.net/