Recent content by sjnt

1. y=y0e^(-ct) 2. after solving for c, y=y0(2/5)^(t/4) y(t)=240(2/5)^(4/4)+240mg=336, correct? 4. n-1 240(sigma)(2/5)^c c=0

i modified the problem statement a bit. I had that equation before but it has to be exponential and it has to be decaying. any thoughts?

Homework Statement Assume that the drug administered intravenously so the concentration of drug in the bloodstream jumps almost immediately to its highest level. The concentration of the drug decays exponentially. A doctor prescribes a 240 milligram (mg), pain-reducing drug to a patient who...

Bump, this is urgent. I finished 1. For 2, would I use D(x)=10 for city A in 30x²-120x+60 and D(x)=20 for city B?

well, how I got that was ∫60t dt for t=x and t=0 ∫60t dt, for t=1 and t=0 + ∫(120-60t) dt, t>1, for t=x and t=1 60=(120x-30x²)-0 eventually, 30x²-120x+60=0. I think that should be correct. Now I'm confused as to whether 2+√2 would be the correct answer (by just solving for x) as opposed to...

Homework Statement A car is traveling on a straight road on a stretch that contains cities A, B, C and D. The distance from city A to city D is 60 miles and the cities are evenly placed along the route. There are cell phone towers in each city. Each tower has a range of 10 miles in all...

nvm i got it.

Ok I differentiated the equation and got: C'(r)=40*pi*r - 27,000,000/(pi*r^2) - 6,750,000/r^2 The dimensions are: r= 41.9385, L=81.4398 Part 2 asks: - The cost of the flooring and siding are stable, but the roofing material has been fluctuating. - In addition to the recommendation for the price...

Ok. Would this be the formula for the sum of the costs? SA=pi*r^2+2*r*L+pi*r*L L=2(255,000)/pi*r^2 C=20$(pi*r^2)+30$(2*r*(2(255,000)/pi*r^2))+$15(pi*r*(2(255,000)/pi*r^2))

The sides are probably the half circles

Homework Statement - Building a half cylinder structure. - The structure must have an exact volume of 225,000 cubic feet. - The current construction costs for the foundation are $30 per square foot, the sides cost $20 per square foot, and the roofing costs $15 per square foot. - Minimize the...