Let {yk}k=1infinity be a sequence of differentiable functions which map [a,b] to Rn. Assume the sequence {yk(a)}k=1infinity is bounded. Assume the sequence of derivatives {yk' }k=1infinity is uniformly bounded: there exists a number M such that ||yk'(t)|| <= M for all t E [a,b] and k = 1,2,3.... Prove that there exists a sub-seqeunce {kj}j=1infinity such that the sequence {ykj}j=1infinity is convergent uniformly in [a,b].
Let {yk}k=1infinity be a sequence of differentiable functions which map [a,b] to Rn. Assume the sequence...
4. Let {S.} be a sequence of differentiable real-valued functions on (a, b) that converges pointwise to a function f on (a, b). Suppose the sequence {f) converges uniformly on every compact subset of (a, b). Prove thatf is differen- tiable on (a, b) and that f'(x) = lim f(x) for all x E (a, b). 4. Let {S.} be a sequence of differentiable real-valued functions on (a, b) that converges pointwise to a function f on (a, b). Suppose...
Let U be an open subset of R. Let f: U C Rn → Rm. (a) Prove that f is continuously differentiable if and only if for each a є U, for each E > 0, there exists δ > 0 such that for each x E U, if IIx-all < δ, then llDf(x)-Df(a) ll < ε. (b) Let m n. Prove that if f is continuously differentiable, a E U, and Df (a) is invertible, then there exists δ...
(2) Let {fJ be a sequence of continuous, real-valued functions that converges uniformly on the interval [0,1 (a) Show that there exists M> 0 such that n(x) M for all r E [0,1] and all n N. (b) Does the result in part (a) hold if uniform convergence is replaced by pointwise convergence? Prove or give a counterexample (2) Let {fJ be a sequence of continuous, real-valued functions that converges uniformly on the interval [0,1 (a) Show that there exists...
(3) Let m,n E N. Let p(x), i -1, ..., m, be polynomials with real coefficients in the variables -(x,..., rn). Prove that pi(r) p(a) Un (r)」 is a continuously differentiable map from R" to R". (Suggestion: Use Theorem 9.21.) (3) Let m,n E N. Let p(x), i -1, ..., m, be polynomials with real coefficients in the variables -(x,..., rn). Prove that pi(r) p(a) Un (r)」 is a continuously differentiable map from R" to R". (Suggestion: Use Theorem 9.21.)
(8) Let E c R" and G C Rm be open. Suppose that f E -G and g:GR', so that h -gof:E R'. Prove that if f is differentiable at a point x E E and if g is differentiable at f(x) є G, then the partial derivatives Dh,(x) exist, for all , SO , . . . , n, and and J-: に1 The subscripts hi, 9i, k denote the coordinates of the functions h, g, f relative to...
Let (an)nen be a bounded sequence in R. For all n e N define bn = sup{am, On+1, On+2,...}. (You do not have to show that the supremum exists.) (a) Prove that the sequence (bn)nen is a monotone sequence. (b) Prove that the sequence (bn)nen is convergent. (c) Prove or disprove: lim an = lim bre. 100 000
5. Let f : R -R be a differentiable function, and suppose that there is a constant A < 1 such that If,(t)| < A for all real t. Let xo E R, and define a sequence fan] by 2Znt31(za),n=0,1,2 Prove that the sequence {xn) is convergent, and that its limit is the unique fixed point of f. 5. Let f : R -R be a differentiable function, and suppose that there is a constant A
5. Let the functions fon : [a, b] → R be uniformly bounded continuous func- tions. Set di, astsb. Prove that F, has a uniformly convergent subsequence.
3. (a) Suppose f : (a, b) + R is differentiable, and there exists M E R such that If'(x) < M for all x € (a, b). Prove that f is uniformly continuous on (a, b). (b) Let f : [0, 1] → [0, 1] be a continuous function. Prove that there exists a point pe [0, 1] with f(p) = p.
***You must follow the comments*** Topic: Mathematical Real Analysis - Let (xn) be a bounded sequence ((xn) is not necessarily convergent), and assume that yn → 0. Show that lim n→∞ (xnyn) = 0. Question1. All the solution state that there exists M >0 and xn<=M . My question is that why M always be bigger than 0 and Why it is bounded above ? why it is not m<=xn bounded below???? Question. 2. if the sequence is convergent, then...