Show that the variables u = x - y + z, v = x + y - z , w = x ^ 2 + xz - xy are functionally related. Find the relationship between them.
Answers
Answer:
Step-by-step explanation:
UNIT 14.8 - PARTIAL DIFFERENTIATION 8
DEPENDENT AND INDEPENDENT FUNCTIONS
14.8.1 THE JACOBIAN
Suppose that
u ≡ u(x, y) and v ≡ v(x, y)
are two functions of two independent variables, x and y; then, in general, it is not possible
to express u solely in terms of v, nor v solely in terms of u.
However, on occasions, it may be possible, as the following illustrations demonstrate:
ILLUSTRATIONS
1. If
u ≡
x + y
x
and v ≡
x − y
y
,
then
u ≡ 1 +
x
y
and v ≡
x
y
− 1,
which gives
(u − 1)(v + 1) ≡
x
y
.
y
x
≡ 1.
Hence,
u ≡ 1 +
1
v + 1
and v ≡
1
u − 1
− 1.
2. If
u ≡ x + y and v ≡ x
2 + 2xy + y
2
,
then
v ≡ u
2
and u ≡ ±√
v.
If u and v are not connected by an identical relationship, they are said to be “independent
functions”.