Answers to WIR wk 10 4.3-4.6, 4.8, 5.1
1. a) x=2 b) 
, the other
solution to the quadratic cannot be used in the original expressions.
c) 
2. a) 
b) 
c) 
d) 
3. 
in hours, or
about .91825 hours , or about 55 minutes.
4. 
days or about
605 days.
5. a) 
b) 2tanx
6. i) L(x)= 5x - 4
ii) 
iii) 
7. 
8. a) 
b) 
c) 
9. a) 0 b)
c) 
d) 
e) 
f)
1
10. a) f is
decreasing 
and increasing
on 
.
f is concave down on 
and on 
.
f is concave up on ( -1 , 1)