If 𝜙(x, y) = 0, show that the determinant
|
fxx + λϕxx
fxy + λϕxy
ϕx
fxy + λϕxy
fyy + λϕyy
ϕy
ϕx
ϕy
|
where 𝜆 is Lagrange’s multiplier, is positive, in case the function attains a maximum.
Let
f
be a differentiable function on
[, ]
and
x [, ].
Show that, if
f (x) 0
and
f (x) 0,
then
f
must have a local maximum at
x.
evaluate limit n tends to infinity [n/(1+n^2) + n/(4+n^2) + n/(9+n^2) +.....+n/2n^2
Show that if n is a natural number and α, β are real numbers with β > 0 then there exists a real function f with derivatives of all orders such that: (i) |f(k)(x)| ≤ β for k ∈ {0, 1, ..., n − 1} and x ∈ (−∞, ∞); (ii) f(k)(0) = 0 for k ∈ {0, 1, ..., n − 1}; (iii) f (n)(0) = α.
Suppose that y = f(x) : (−∞, ∞) → (−∞, ∞) is infinitely differentiable and has a local minimum at 0. Prove that there exists a disc centered on the y axis which lies above the graph of f and touches the graph at the point (0, f(0)).
] Show that if n is a natural number and α, β are real numbers with β > 0 then there exists a real function f with derivatives of all orders such that: (i) |f(k)(x)| ≤ β for k ∈ {0, 1, ..., n − 1} and x ∈ (−∞, ∞); (ii) f(k)(0) = 0 for k ∈ {0, 1, ..., n − 1}; (iii) f (n)(0) = α.
Use POLYA'S FOUR-STEP PROBLEM SOLVING STRATEGY to solve the problems.
show that the inequalities satisfies for all point x,y∈R
d*(x,y) ≤d(x,y)≤√n d*(x,y)