indefinite integrals
FTC pt 1 and 2
Differential Equations
2 dimensional DEs
miscellaneous
100

Evaluate the integral:

int (6x^8 -20x^4+x^2+9)dx

2/3x^9-4x^5+1/3x^3+9x+c

100

Find:

int_-1^0x^3(1-2x^4)^3dx

0

100

Find and give the stability of the equilibria of:

y' = (y^2-4)(y+1)^2

2 = unstable, -2 = stable, -1 = semi-stable

100

How do you pass X nullclines? Y nullclines?

X nullclines: Vertical

Y nullclines: Horizontal

200

Evaluate the integral:

int sin^2(x)cos(x)dx

1/3sin^3(x)+c

200

Evaluate:

(d/dx)int_4^(x^2)e^(x^2)dx

2xe^(x^4)

200

In a city having a fixed population M, the time rate of change of the number N of those persons who have heard a certain rumor is proportional to the number of those who have not yet heard the rumor. Write the differential equation.

(dN)/dt=k(M-N)

200

Describe what is happening in each quadrant for a sample predator-prey model assuming y axis is predator

I: Both predator and prey populations are decreasing

II: more prey, fewer predators

III: more prey, more predators

IV: more prey, less predators


300

Evaluate the integral:

int 4(1/x-e^-x)cos(e^-x+lnx)dx

4sin(e^-x+lnx)+c

300

Find:

int_(1/e)^e (lnx)^3/x dx

0

300

Use Euler's method to approximate p(2), using a step size of 1.

(dp)/dx=0.5x(1-x),p(0)=2

 

2

300

Use Euler's method to approximate t(0.2), using a step size of 0.1.

y'+2y=2-e^(-4t)

y(0)=1

0.853

300

Given a function

y=x^2

, find the Left Riemann Sum of the function on the interval [0,6] divided into three sub-intervals.

40

400

Evaluate the integral:

int (3x)/(x^2+2x-8)dx

2lnabs(x+4)+lnabs(x-2)+c

400

Does the following converge or diverge?

Find:

int_1^oo dx/(x^2-1)

Diverges aka 

oo

400

Find the general solution:

dy/dt=2y(t^2+1)

y=Ae^(2/3t^3+2t)

500

Evaluate the integral:

int x^7sin(2x^4)dx

-1/8x^4cos(2x^4)+1/16sin(2x^4)+c

500

Evaluate:

int_1^oo (lnx)/x^2 dx

1

500

Solve given the conditions.

(dy)/dx=(x+x^3)/y^2 , y(1)=1

y = ((6x^2+3x^4-5)/4)^(1/3)

500

For the following system of differential equations, plot the nullclines and find the equilibria.

(dr)/dt=-r(2-s), (ds)/dt=s(3-r)

Plot direction arrows and a plausible solution in the phase plane for the initial conditions r(0)=1 and s(0)=1.