Review questions: Logarithms TRUE or FALSE MATH 121

I. The exponential function bx = y

______ a.          domain (x) is all Real Numbers

______ b.          domain may include Z+, Z-, Q +, Q -, I+, I-

______ c.          b is always > 0

______ d.          Range (bx) is always > 0

______ e.          If b > 1, graph looks like:    wpeA.jpg (1778 bytes)

______ f.          If b < 1, graph looks like:        wpe9.jpg (1715 bytes)

______ g.          If b < 0, graph looks like :         wpe8.jpg (1754 bytes)

 

II. The logarithmic function Logbx = y

______ a.          is the inverse of y = bx

______ b.          domain (x) > 0

______ c.          Range (y) is all reals

______ d.          If graph of y = bx is                  wpe7.jpg (2017 bytes)

                         then graph of logbx = y is             wpe6.jpg (2034 bytes)

______ e.          b is always positive (usually > 1)

______ f.         b ≠ 1

______ g.          y = logbx is equivalent to by = x

III.

______ a.          A log can be negative.

______ b.          You can take the log of a negative number.

______ c.          A log can be 0.

______ d.          You can take the log of 0.

______ e.          logbx - 1 = logb(x - 1)

 

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______ f.          logb(x - 1) = logbx - logb1

______ g.          logbx(1/2) = 1/2 logbx =

______ h.           = logbx - logb2

______ i.         

______ j.          (logbx)3 = 3 logbx

______ k.          (x - 1)log 3 = x log 3 - log 3

______ l.          = 2

______ m.          logbbn = n

______ n.          = N

______ o.          logb1 = 0

______ p.          If 0 < N < 1, then log N < 0

______ q.          logb(xb) = logbx + 1

______ r.          If f is an exponential function and f(2) = , then f(x) = 3-x

______ s.          If f is an exponential function and f(2) = , then b = -3

______ t.           If log(1/3)x = -2, then log3 = -2