Practice Quiz 6.1−6.3 Answers

1)  Inverse is 7/(x − 4); Domain is x can not be 0; Range is y can not be 4

2)  a)  1/70                   b)   8                c)  ½ or –3                 

3)  t is about −0. 31   

4) a) x is greater than 5           b)  x is less than −7 or bigger than 1              c) x is less than −4 or bigger than 1 

5) 102400                   

6)  a) x = 4 (check!)                b) 8/13             c) 1/2

7)  (–1, 6)       

8) The inverse is (x+1)/(x −2)            

9) Show both composition = x

10) −7/2          

11) Answers vary, base must be bigger than 1         

12) a≠1; (0, 1), because a raised to 0 is always equal to 1

13)  Answers may vary, the function is undefined when x=0 or negative because…

14)  0.30118…. or to be exact 7^6 divided by 5^8      

15)  Answers may vary, any odd function is good such as y = x+7 or y = x^5…etc.

16)  Exponential growth shifted up 2 units and right 3 units.  Horizontal Asymptote at y = 2.  Domain:  All real numbers.  Strictly increasing

17)  j(x); if the base is bigger than 1 it will grow and the bigger the base, the faster it grows.

18)  Start with the graph of e^x (exp growth), reflected over the line y=x, gives you the graph of y = lnx.  Then shift left 3 units.  x = −3 is vertical asymptote.  It is an increasing function.  Domain: x>−3

19)  3 because 10^3 is a 1000