1549901369-Elements_of_Real_Analysis__Denlinger_

(jair2018) #1

  1. Let l(x) = 4 - x^2. Find
    (a) 1J(f)
    (c) l[O, 1]
    (e) 1(0, 2)
    (g) 1-^1 [2, 4]
    (i) 1-^1 (0, 00)
    (k) 1-^1 ({0})

  2. Let l(x) = 2x. Find
    (a) 1J(f)
    (c) l[O, 1]
    (e) 1(0, oo)
    (g) 1-^1 [1, 2]
    (i) 1-^1 [-l, 1)


B.3 Algebra of Real-Valued Functions 625

(b) R(f)
(d) 1-^1 [0, 1]
(f) 1-^1 (0,4)
(h) 1-^1 [-4,0]
(j) 1-^1 ( -oo, 2]
(1) 1-^1 ({-l})

(b) R(f)
( d) I (-oo, 2)
(f) l[-1, ~]
(h) 1-^1 (2,8)
(j) 1-^1 (-00,0)


  1. Redo Example B .2.12 using the function l(x) = 4 - x^2 instead of the
    function given there.

  2. Redo Example B.2.12 using the function l(x) = x^3 - 3x^2 instead of the
    function given there.

  3. Prove Theorem B.2.11 (b).

  4. Prove Theorem B.2. 11 (c).

  5. Prove Theorem B.2. 11 (d).

  6. Prove Theorem B.2. 11 (f).

  7. Prove Theorem B.2. 13 (a) (1).

  8. Prove Theorem B.2.13 (a) (2).


12. Prove Theorem B.2. 13 (b) (1).


  1. Prove Theorem B.2.13 (b) (2).


B.3 Algebra of Real-Valued Functions


Definition B.3.1 Let S denote an arbitrary set. Any function I : S -+JR. is
called a real-valued function on S. We shall consider the set of all such
functions,


:F(S, JR.)= {all functions I: S -+JR.}.

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