Question

The formula P=0.64x^2-0.049+2 models the approx population P, in thousands, for a species of fish in a local pond, x yrs after 1997. During what yr will the population reach 42,568???

2004,2005,2006, or 2007

Answer 1

put P=42,568 and solve for x, and then add x to 1997 to find the answer

Answer 2

So solve for P first than add x to 42,568?

Answer 3

noo, the population is equalto 42,568 in a certain year, that's what we want to find... that year. to get that year, we know that x is the number of years after 1997 for which the population will be equal to 42,568... so we find x and add it to 1997 and voila, we know the year. :) is that making any sense so far?

Answer 4

so 42,568=0.64x^2-0.049x+2 is the equation right? I think thats what I understood by what you just wrote

Answer 5

exactly... then we find x

Answer 6

I got x as 42,29,and -29

Answer 7

no that is not the right equation i don't think, because it gives the population in thousands

Answer 8

Well Mr. Satellite73 help plz [=

Answer 9

try this one
\[
42.568 = 0.64 x^2-0.049+2\]

Answer 10

http://www.wolframalpha.com/input/?i=42.568%3D0.64x%5E2-0.049%2B2

Answer 11

looks like the answer is closest to x = 8 so 8 years after 1997

Answer 12

aka 2005

Answer 13

Thank you [=

Answer 14

I think she missed the x after the 0.049 in her original question cos i noticed she wrote that in her reply.... so that makes it a quadratic, but i could be wrong

Answer 15

Yeah I missed the x after -0.049x

Answer 16

and btw why did u write 42.568 <<< and not 42,568 ?

Answer 17

because it says it gives the answer in thousands
so if you get P = 4 that means 4,000

Answer 18

the answer appears to be 8
i redid it
http://www.wolframalpha.com/input/?i=42.568%3D0.64x%5E2-0.049x%2B2

Answer 19

yeah it is, i solved it and it's approximately 8 so yeah :)

Answer 20

wolfram says 8 when i redid it

Answer 21

Gracias you guys I loved the help

Answer 22

anytime :)

Answer 23

yw