Slope Fields
Growth/Decay
Separation of Var.
Derivatives
Timed Unit Circle
100

Is this a slope field for a differential equation with x, a differential equation with y, or a differential equation with x & y?  

differential equation with x

100

The rate of change of N with respect to t is proportional to (500 - t).  Write this as a mathematical equation.  

(dN)/dt = k(500 - t)

100

Separate the variables for the differential equation. 

dy/dx = 5xy

dy/y = 5xdx

100

State the derivative of 

sec(x)

sec(x)tan(x)

100

Find the exact value of 

cos(pi/6)

sqrt(3)/2

200

Is this a differential equation with x, a differential equation with y, or a differential equation with x & y? 

a differential equation with x & y

200

Population y grows according to the equation dy/dt = ky, where k is a constant and t is measured in years.  If the population doubles every 15 years, what is the value of k? Give an exact answer. 

k = ln(2/15)

200

Find the general solution for y: 

dy/dx = (x + 1)/y

y=+-sqrt(x^2+2x+C

200

State the derivative of 

csc(3x)

-3csc(3x)cot(3x)

200

Find the exact value of 

tan((3pi)/2)

Undefined

300

For the slope field pictured, when is dy/dx undefined? Answer in the form of an equation.

y = 0

300

A baby weighs 6 lbs at birth and 9 lbs 3 months later.  If the weight of the baby is increasing at a rate proportional to its weight.  Find the value of k.  Give answer as an exact value.

k = ln(1.5)/3

300

Solve the initial value problem explicitly. 

dy/dx = -x/y

(3, 4) 

y = sqrt(-x^2+25)

300

State the derivative of ln(x2) in simplified form with positive exponents. 

2/x

300

Find the exact value of 

csc(pi/3)

(2sqrt(3))/3

400

When does the slope field have a slope of -1?  Answer in the form of an equation.

y=-x-1

400

Bacteria in a certain culture increases at a rate proportional to the number present.  If the number of bacteria doubles every four hours, in how many hours will the number of bacteria triple?  Round to 2 decimal places.

t = 6.34 

400

Solve the initial value problem explicity.

dy/dx =sin(5x + pi);

y = 2 when x = 0.

y = -1/5cos(5x + pi) + 9/5

400

Calculate the derivative of y = 5(x2+17)2.  Give anwer in simplified form. 

y' = 20x3 + 340x

400

Find the exact value of 

sec((-3pi)/4)

-sqrt(2)

500

The slope field for a differential equation is shown.  Which statement(s) is/are true for solutions of the differential equation? 

I.  For x < 0, all solutions are decreasing.   

II.  All solutions level off near the x-axis.  

III.   For y > 0, all solutions are increasing.

II and III only 

500

Newton's Law of Cooling states that the rate of change in the temperature of an object is proportional to the difference between the object's temperature and the temperature in the surrounding area.  A detective finds a murder victim at 9 am with a body temp of 90.3 degrees.  1-hour later, the temperature of the body is 89 degrees.  The room is kept at 68 degrees (eq: dT/dt = k(T - 68)) Assuming the body was 98.6 degrees at time of death, at what time did the murder occur?  Approximate to the nearest 1/4 hour. 

3:45 am 

500

Solve the initial value problem explicitly. 

dy/dx =y/(9 + x)

 for (0, 18) 

y = 2x + 18

500

Find dy/dx if 

3xy = 4x + y^2

(4 - 3y)/(3x - 2y)

500

sin((2pi)/3)-cos((2pi)/3)

Give the exact value of the expression above as a single fraction. 

(sqrt(3) + 1)/2