Vector Calculus Flashcards
Distance Formula for (x,y,z)
PQ = ( (x1 - x2)2 + (y1 - y2)2 + (z1 - z2)2 )1/2
magnitude of v
||v|| = ( a2 + b2 + c2 )1/2
vector components
P = point (a,b,c)
Q = point (d,e,f)
PQ = < d - a , e - b , f - c>
midpoint formula
(a,b,c) + 1/2 * PQ
or
< (a1 + 2)/2 , (b1 +b2)/2 , (c1 + c2)/2 >
dot product
v * w = a1*a2 + b1*b2 + c1*c2
v * w = ||v|| * ||w|| * cos Ø
v * v = ||v||2
unit vector = ev
v / ||v||
vector projection of u onto v
u||
u|| = ( (u * v) / (||v||2) ) * v
u|| = (u * ev) * ev
u|| = ( (u * v) / (v * v) ) * v
parallel vectors
if lines through w and v are parrallel
or
w = Cv
for scalar C not equal to 0
equation of a sphere
of radius R
centered at (a, b, c)
(x - a)2 + (y - b)2 + (z - c)2 = R2
equation of a cylinder
of radius R
whose center line is the vertical axis through (a, b, 0)
(x - a)2 + (y - b)2 = R2
magnitude of projection
of u along v
||u|||| = ||u|| * cos Ø
Cross Product
v X w
orthogonal to v and w
v X w = - (v X w)
v X v = 0
v X w = 0 iff w = Cv or v = 0
length of v X w
||v X w|| = ||v|| * ||w|| * sinØ
||v X w||2 = ||v||2 * ||w||2 - (v * w)2
scalar projection of u onto v
or
the component of u along v
u * ev
where ev = v / ||v||
a vector v is orthogonal to w
if and only if
v * w = 0
the angle Ø between v and w is obtuse/acute
v * w < 0 is obtuse
v * w > 0 is acute
the decomposition of u with respect to v
u = u|| + uperp
where uperp is orthogonal to v
C * v X w = v X (C * w) =
= C (v X w)
(u + v) X w =
= u X w + v X w
translation
a vector v undergoes a translation when it is moved parallel to itself
without changing length or direction
w is the translate
equivalent
v and w are equivalent if w is a translate of v
linear combination
(if v and w are not parallel)
u = r * v + s * w
parallelogram spanned
parallelogram whose vertices are the origin and the terminal
points of v, w, and w + v
consists of linear combination
where 0
The line L through P0 = (x0 , y0 , z0) in the direction
of (parallel to) **v; ** where O is origin
vector parametrization :
parametric equation:
r(t) = OP0 + v = < x0 , y0 , z0> + t *
x = x0 + at ; y = y0 + bt ; z = z0 + zt