Let Eo denote the set of all interior points of a set E. Prove: E is open if and only if Eo= E
REAL ANALYSIS Question 1 (1.1) Let A be a subset of R which is bounded above. Show that Sup A E A. (1.2) Let S be a subset of a metric space X. Prove that a subset T of S is closed in S if and only if T = SA K for some K which is closed in K. (1.3) Let A and B be two subsets of a metric space X. Recall that A°, the interior of A,...
hal 5. Let CR denote the r Prove curve 1«R for some R21 au alying on Ce.
hal 5. Let CR denote the r Prove curve 1«R for some R21 au alying on Ce.
only the last question plz
2. Let S be a set and let ~ be an equivalence relation on it. Let π denote the canonical projection, T: S → S/ ~, π(x) = [x] . Prove that π is an onto map. Give an example of a set and relation for which π is not one-to-one. What is the necessary and sufficient condition on ~ for π is one-to-one? (State your answers and prove them
2. Let S be a...
Please answer all parts. Thank you!
20. Let R be a commutative ring with identity. We define a multiplicative subset of R to be a subset S such that 1 S and ab S if a, b E S. Define a relation ~ on R × S by (a, s) ~ (a, s') if there exists an s"e S such that s* (s,a-sa,) a. 0. Show that ~ is an equivalence relation on b. Let a/s denote the equivalence class...
1. Recall the definition of red, green, blue numbers. Let R denote the set of red numbers. Let G be the set of green numbers, and let B denote the set of blue numbers. Is R S G S B = Z. Here Z is the set of all intergers. Explain.
B2. (a) Let I denote the interval 0,1 and let C denote the space of continuous functions I-R. Define dsup(f,g)-sup |f(t)-g(t) and di(f.g)f (t)- g(t)ldt (f,g E C) tEI (i) Prove that dsup is a metric on C (ii) Prove that di is a metric on C. (You may use any standard properties of continuous functions and integrals, provided you make your reasoning clear.) 6 i) Let 1 denote the constant function on I with value 1. Give an explicit...
(23) Let S- 25 125 6. Prove that S is a den 25 Prove that S is a denumerable set (24) (a) Prove that Q has no interior points. (b) Prove that Ir, the set of irrational numbers has no interior points.
Let R denote the ring of Gaussian integers, i.e., the set of all complex numbers a + bi with a, b ∈ Z. Define N : R → Z by N(a + bi) = a^2 + b^2. (i) For x,y ∈ R, prove that N(xy) = N(x)N(y). (ii) Use part (i) to prove that 1, −1, i, −i are the only units in R.
(18) Let f and g be functions from R to R that have derivatives of al orders. Let h(k) denote the kth derivative of any function. Prove using the product rule for derivatives, the fact that and induction that k +1 k=0 (19) The Fibonacci numbers are defined recursively by Fn+2 = Fn+1 Prove that the number of subsets of { 1, 2, 3, . . . , n} containing no two successive integers is E, (20) Prove that 7n...