I am back

[mudfish]

Find the maximum value:
f(t) = -16t^2 + 48t + 300

Solve the exponential equation for t:
5 = 10e^-.00002845t

[NoteMe]

First derivate the first thingy:


f ' (t) = -32t + 48


Then set that one = zero

-32t + 48 = 0

32t = 48

t = 48/32
t = 3/2


thats where t is max/min

Now put t into the first thingy and see what you get.

f(3/2) = -16*(3/2)^2 + 48*(3/2) + 300

No idea what that is....and you are not getting me to find some peace of paper to calculate it either..


************************************************'

[wossname]

I just interpolated with my calculator...

Max is where x=1.5, y=336

[azteched]

5 = 10e^-.00002845t

divide both sides by 10

1/2 = e^-.00002845t

take natural logs

ln(1/2) = -.00002845t

or (since -ln(2) = ln(1/2)):

t = ln(2)/.00002845

[mudfish]

Thanks for the help, she want me to check her work!

She knows I not had math in 18 years.