Diffeq Warmup
Vector Calculus
Integration
Applications of Integration
100

The verification step showing 

u(t) = 2 + Ce^(-t/5)

is the solution to the differential equation

u'(t) = 2/5 - 1/5u(t)

u'(t) = -C/5e^(-t/5)

2/5 - 1/5(2 + Ce^(-t/5)) = 2/5-2/5-C/5e^(-t/5)

2/5 - 1/5(2 + Ce^(-t/5)) = -C/5e^(-t/5)=u'(t)

100

The acceleration of a particle, at t=3 seconds, whose velocity at time t is given by 

v(t) = langle 8t^3, t-2 rangle (ft)/s

a(1) = langle 216, 1 rangle (ft)/s^2

a(t) =v'(t) = \langle 24t^2, 1 \rangle (ft)/s^2

100

The formula for integration by parts, if

int u dv


uv - int vdu

100

The definite integral representation of the area of the region bounded above by 

f(x) = 9 -(x/2)^2

and below by

g(x) = 6-x

int_(-2)^6 [(9 -(x/2)^2) - (6-x)] dx

Find where f(x) and g(x) intersect by setting f(x)=g(x) and solve for x.

200

The equilibrium solutions to the differential equation

(dP)/(dt) = (P+1)(e^(2-P)-1)

P=-1, P =2

(P+1)(e^(2-P)-1)= 0 

P+1 = 0 \Rightarrow P = -1

e^(2-P)-1= 0 \Rightarrow P = 2

200

The integration technique used to integrate

int tln(t) dt

Integration by parts

u = ln(t)

dv = t dt

300

Correct labeling of the equilibrium solutions P=5, P=12, and P=102 given that 

P'(2)>0

P'(8)>0

P'(14)<0

P'(2000)>0

P=5: semistable

P=12: Stable

P=102: Unstable

300

The speed of a particle, at t=1 seconds, whose velocity at time t is given by 

v(t) = langle 8t^3, t-2 rangle (ft)/s

sqrt(65) (ft)/s

v(1) = \langle 8, -1\rangle (ft/s)

||v(1)|| = sqrt(8^2+(-1)^2)=sqrt(65)

300

Using substitution, what is the u and du for 

int sin(x)cos(x) dx

u = sin(x), du = cos(x) dx

or 

u = cos(x), du = -sin(x) dx

300

The definite integral representation of the mass of a 7 cm long wire where the wire density is represented by 

rho(x) = (14x+1) g/(cm)

int_0^7 rho(x) dx = int_0^7 (14x + 1) dx

400

The arclength of a particle, between t=0 s and t=1 s, whose position at time t is given by 

r(t) = langle cos(18t), sin(18t) rangle (ft)

 18ft

\int_0^1 norm(r'(t))dt = int_0^1 norm(\langle -18sin(t), 18 cos(t) rangle)dt

int_0^1 sqrt(324(sin^2(t) + cos^2(t))) dt

int_0^1 sqrt(324) dt

400

The integration technique used to integrate

int (2t)/(t^2+1) dt

Substitution

u=t^2 + 1

du = 2t dt

400

The definite integral representation of the volume of a cone whose base has a radius of 5m and a height of 12m.

int_0^12 pi (-5/(12)x+5)^2 dx




500

The most accurate approximation of y(10) given that y(4) = 12, using the following table:

20

y(6) approx y(4) + hy'(4) = 12 + 2(-4) = 4

y(8) approx 4 + 2y'(6) = 10

y(10) approx 20

500

The integration technique used to integrate

int (4)/(4y - y^2) dy

Partial Fraction decomposition

(4)/(4y - y^2) = A/y + B/(4-y)

500

The definite integral representation of the hydrostatic force in the given image. 

rho = 1000, g=9.8

int_0^8 9800x(4+x/2)dx