Originally Posted by
b_austintx ok i have two questions that i need help on. ugh word problems...
1. a car tire has a small leak, and the tire pressure in pounds per square inch after t minutes is given by
P(t) = 32e (-0.2t) After how many minutes was the pressure 5 pounds per square inch?
*note the (-0.2t) is the exponent.
there is not time- so i'm not sure what to plug into (t)? plug in (60) for (t) since its talking about minutes?? and since its neg. i keep getting a neg. answer. but there is no such thing as a neg min. so i'm stuck....
2. Suppose $8000 is invested into a savings account that accrues intrest continuously at a rate of 2.3% determine how long it would take the investment to triple.
its continuously...there is no year or quartly so how do i solve?
i think the formula to use is
A=P (1 + r/t) ^ nt -----is this right?
what do i do for t? apparently time that i have the problem with in both questions.
can anyone help?