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# Real Analysis

### Double Integral: Horizontal and Vertical Simple Methods

I have managed to evaluate the double integral using the horizontal simple method, and answer 63. But when I reverse the order (vertical simple method) I cannot reach the same answer of 63, I get 65. 1) Evaluate the double integral of f(x,y)=x+4y^2 over the triangular region with vertices (-2,2) (4,2) & (1,-1) Check that r

### Real Analysis : Mean Value Theorem

Let f(x) be integrable on [a,b], and let g(x) be nondecreasing and continuously differentiable on [a,b]. Let {p be element of P} be a partition of [a,b], and define U(f,g,p) = SIGMA (Mi(g(the ith term of x) - g(the (i-1)th term of x))) as i=1 to n L(f,g,p) = SIGMA (Ni(g(the ith term of x)-g(the (i-1)th term of x))) as i=1 t

### Real Analysis : Proof

I need a proof for "If f on [a,b] is continuous & 0 is not a member f([a,b]) then f is bounded away from 0."

### Real Analysis : Proof using Summation Integrals

For numbers a1,....,an, define p(x) = a1x +a2x^2+....+anx^n for all x. Suppose that: (a1)/2 + (a2)/3 +....+ (an)/(n+1) = 0 Prove that there is some point x in the interval (0,1) such that p(x) = 0

### Real Analysis :Problem Prove a function is integrable over [a,b]

Let f:[a,b] mapped to the Reals be a function that is integrable over [a,b], and let g:[a,b] mapped to the Reals be a function that agrees with f except at two points. Prove g is integrable over [a,b].

### Real Analysis : Integrability

Prove that if f : [a,b] ----> R is a bounded function that is continuous at all but finitely many points, then f is integrable over [a,b].

### Radius of Convergence

The problem is to determine the radius of convergence of the Taylor Series for each of the functions below centered at x. We are to explain our conclusion in each case. I would like to see how to work each problem (including what the Taylor Series is) and what the explanation is. a) centered at and NOTE: I know the

### Taylor polynomial approximation

Suppose that the function F:R->R has derivatives of all orders and that: F"(x) - F'(x) - F(x) = 0 for all x F(0)=1 and F'(0)=1 Find a recursive formula for the coefficients of the nth Taylor polynomial for F:R->R at x=0. Show that the Taylor expansion converges at every point.

### Infinite Series of Real Numbers (Absolute Convergence)

Please see the attached file for the fully formatted problem. Define ak recursively by a1 = 1 and ak = (&#8722;1)k  1 + k sin  1 k  &#8722;1 ak&#8722;1, k > 1. Prove that P 1k =1 ak converges absolutely. Since this problem is an analysis problem, please be sure to be rigorous.

### Infinite Series of Real Numbers (Cesaro summable)

Infinite Series of Real Numbers (Cesaro summable)

### Functions : Convergence and Limits

Please see the attached file for the fully formatted problems. Let f be a real function defined by . 1) Evaluate f'(x), f''(x), f(0). Show that f has exactly two roots and , with . Find an interval of two consecutive real numbers within which the roots must lie. From now on, let us denote and these two (closed) in

### Power and Taylor series

Interval of Convergence of a power series a. Consider the Power series sum of series from n=1 to infinity of FnX^n. Use the ratio test to determine the open interval on which the pwr series converges. b. Show that the Taylor series of the Fcn f(x) = x/(1-x-x^2) about x=0 is given by: x/(1-x-x^2) = sum of series at

### Real Analysis : Young's Inequality

Note: * = infinite Suppose that the function f:[0,*)->R is continuous and strictly increasing, with f(0) = 0 and f([0,*)) = [0,*). Then define F(x) = the integral from 0 to x of f and G(x) = the integral from 0 to x of f^-1 for all x>=0 (a) Prove Young's Inequality: ab <= F(a) + G(b) for all a >= 0 and b >= 0 (b) N

### Real Analysis: Geometric Interpretation in Terms of Areas

Note: * = infinite Suppose that the function f:[0,*) -> R is continuous and strictly increasing, and that f:(0,*) -> R is differentiable. Moreover, assume f(0) = 0. Consider the formula: the integral from 0 to x of f + the integral from 0 to f(x) of f^-1 =xf(x) for all x>= 0. How can I provide a geometric interpretation

### Real Analysis: Criteria for Integrability

Suppose the continuous function f:[a,b]->R has the property that: The integral from c to d f<=0 whenever a<=c<d<=b Prove that f(x)<=0 for all x in [a,b]. Is this true if we require only integrability of the function?

### Real Analysis of Criteria for Integrability

Suppose that the function f:[a,b]->R is integrable and there is a postive number m such that f(x) >= m for all x in [a,b]. Show that the reciprocal function 1/f:[a,b]->R is integrable by proving that for each partition P of the interval [a,b], U(1/f,P) - L(1/f,P) <= 1/m^2[U(f,P) - L(f,P)]

### Real Analysis: Criteria for Integrability

Define f(x) = x^2 for all x in [0,1]. For each natural number n, compute L(f,Pn) and U(f,Pn), where Pn is the regular partition of [0,1] into n subintervals.Then use the Integrability Criterion to show that the function f:[0,1]->R is integrable.

### Real Analysis - Riemann Integrability

Please see the attached file for the fully formatted problems. Prove that if f is integrable on [0, 1], then lim n !1 Z 1 0 x n f(x)dx = 0 Since this problem is an analysis problem, please be sure to be rigorous. It falls under the chapter on Integrability on R , where they define partition, refinement of a partition,

### Real Analysis: Riemann Integrability

Please see the attached file for the fully formatted problem. Let E = { 1/n : n 2 N } . Prove that the function f(x) = ? 1 x 2 E 0 otherwise is integrable on [0,1]. What is the value of R 1 0 f(x)dx? Since this problem is an analysis problem, please be sure to be rigorous. It falls under the chapter on Integrabili

### MacLaurin Series And Laplace Transforms : Absolute Convergence

Find MacLaurin Series for the given function f. Use the linearity of the Laplace Transform to obtain a series representation L(f)=F(s) Determine 5 values for which the series converges absolutley (and uniformly). Also show the Laplace transform exists, i.e. that it has exponential order alpha. Here are the functions. A) f

### Proof by induction that a polynomial of degree n>0 has at most n roots.

A polynomial of degree n>0 has at most n roots. (A root of a function is a point at which the function has value 0.) I need a proof by induction to show this.

### Real Analysis : Derivatives

If I say that the function f:R->R has two derivatives, with f(0) = f'(0) = 0 and the absolute value of f"(x) is less than or equal to one, if the absolute value of x is less than or equal to 1. How can I prove that: f(x) <= 1/2 if x <= 1

### Real Analysis: Differentiation Function

If I let the function f:R->R have two derivatives with f(0) = 0 and f'(x) <= f(x) for all x in R. Is f(x) = 0 for all x in R

### Real Analysis : Proof of a Constant

Please see the attached file for the fully formatted problem. Let > 0. Prove that log x  x for x large. Prove that there exists a constant C such that log x  C x for all x 2 [1, 1 ), C ! 1 as ! 0+, and C ! 0 as ! 1 Please justify all steps and be rigorous because it is an analysis problem. (Note: The probl

### Real Analysis: Mean Value Theorem

Let r e-1/x2 i(x) = i 0 x740 x = 0 Show that the nth derivative of 1(x) exists for all n E N. Please justify all steps and be rigorous because it is an analysis problem. (Note: The problem falls under the chapter on Differentiability on IR in the section entitled The Mean Value Theorem.)

### The inverse cosine function has domain

The inverse cosine function has domain [-1,1]and range [0, pi]. Prove that (cos^-1)'(x) = -1/ sqrt(1-x^2). This needs to be proved from a real analysis point of view not a calculus.

### Composition Series

Write a composition series for the rotation group of the cube and show that it is indeed a composition series.

### Series Convergence: Two-sided Estimator

Please see the attached file for the fully formatted problems. A simple technique to estimate values of the finite sums of reciprocals to natural numbers raised to positive power and to define if corresponding infinite series converge. Deduce two-sided estimator for the sums of the positive powers (p) of reciprocals to nat

### Evaluating Limits: Epsilon-Delta Definition and Limit Theorems

Evaluate the following limits using the epsilon - delta definition and the limit theorems. a) lim {x -> 0} sin x sin (1/x^2) b) lim {x -> Infinity} (x^3 + 1)/(x^3 cos(1/x) + x^2 - 1) Please also show how you came up with the answer.

### Limits of Functions Using Epsilon

Evaluate the following limits using the epsilon - delta definition and the limit theorems: a) lim {x -> 0} (x^2 + cos x)/(2 - tan x) b) lim {x -> sqrt(pi)} ((pi - x^2)^(1/3))/(x + pi)