Recent content by Incog

Bump.

Homework Statement 60% of all machines inspected were 20 years or older. Give a percentile ranking for the age of 20 years in the distribution of all ages of inspected machines. Homework Equations Don't think there are any that apply to this question :/ I found this equation...

Homework Statement A bacteria culture starts with 1000 bacteria and grows to a population of 7000 after an hour. a) Find the size of the population after t hours. b) Find the size of the population after 3 hours. c) Find the rate of growth of the population after 3 hours. d) When will...

I'm not sure I understand.

Homework Statement A water tank is built in the shape of a circular cone with a height of 6 m and a diameter of 10 m at the top. Water is being pumped into the tank at a rate of 2m^{3} per minute. Find the rate at which the water level is rising when the water is 2 m deep. Homework...

Yes, I checked and checked again and that is the equation. What if I were to plug in a value slightly greater than 1? Would that give me the rate of change after one hour?

Homework Statement Suppose that t hours after a piece of food is put in the fridge its temperature (in Celsius) is T(t) = 15 - 3t + \frac{4}{t - 1} where 0 \leq t \leq 5. Find the rate of change of temperature after one hour. The Attempt at a Solution Since it's asking for...

Thanks. That cleared the confusion. :cool:

Homework Statement A: Write f(x) = \sqrt{5-x^{2}} as a composite of two functions. B: Use the Chain Rule to find the derivative of f(x) = \sqrt{5-x^{2}} Homework Equations Chain Rule: y`= \frac{dy}{du} \frac{du}{dx} The Attempt at a Solution A: y = \sqrt{u} u = 5 -...

Homework Statement I have to do a few graphs and some equations with certain domains but I've never seen the domain written in this way: Usually I see the domain written with something like 2<x<4. What exactly does the above mean?

Homework Statement A liquid is being poured onto a level surface making a circular pattern on the surface. Find the rate of change of the area covered on the surface with respect to the radius when the radius is 20cm. Homework Equations Surface area = (Pi)r^2 The Attempt at a...

Homework Statement Guy records data of person using a swing. Comes up with an equation to show his findings: y = 1.6sin(1.8x - 0.9) + 2.5 What does each number represent in relation to the situation (person swinging)? Homework Equations Don't think any equations are needed for...

Oh yeah, just saw that. And that's the way the teacher taught it to us. What's the shorter way?

Alright I think I got it: 2x^2 - 40x + 400 = 2(x^2 - 20x) + 400 = 2[x^2 - 20x + (20/2)^2 - (20/2)^2] + 400 = 2[x^2 - 20x + 10^2 - 10^2] + 400 = 2[(x-10)^2 - 100] + 400 = 2(x-10)^2 + 400 - 200 = 2(x-10)^2 + 200 10 being the two squares 200 being the least possible sum

Homework Statement The sum of two numbers is 20. What is the least possible sum of their squares. 2. The attempt at a solution Before I show my work, I'm pretty sure I have the answer. I think it's 200. If you add 10 and 10, you will have 20. If you square 10 you get 100, thus the sum...