Question

How to figure out the temperature of a lake using x for the feet or the Depth and for the degrees Celsius, use (3900x+1000) /(3x^2+100) with the answer of the degrees Celsius being 6.74 looking like

6.74=(3900x+1000)/(3x^2+100)
i need the depth

i have figure out that
a=-20.22
b= 3900
c= 326

On the quadratic formula table

-3900+Square root ()/-40.44

Answer 1

Yes, the quadratic formula is:
x=(-b±√(b²-4ac))/(2a)

what you need inside the square-root sign is
b²-4ac

Answer 2

You will get two roots for x.
Reject the negative one, and retain the positive root which is a little under 200.

Answer 3

Thank you
My professor told me to go to the math lab and they could help on a white board thank you for all you help if I knew going back to school I wouldn't have done it at the wise age of 60

Answer 4

No problem.
Let us know any time if you need further help.

Answer 5

i do that just confused me even more