MHR • Advanced Functions 12 Solutions 660

Chapter 7 Section 2
Techniques for Solving Exponential
Equations
Chapter 7 Section 2 Question 1 Page 375
Substitute x = 4 into all the equations to find a point.
Match the graphs to the equations using the point found.
!
i) y = 100 1 $
"
# 2%
&
= 100
16
= 6.25
4
!
ii) y = 50 1 $
"
# 2%
&
= 25
4
4
!
iii) y = 50 1 $
"
# 2%
&
= 50
16
= 3.125
4
!
iv) y = 100 1 $
"
# 2%
&
= 50
4
4
a) iii) b) i) c) ii) d) iv)
Chapter 7 Section 2 Question 2 Page 375
a) log 2 = log1.07 t
log 2 = t log1.07
t = log 2
log1.07
t &= 10.24
b) log3 = log1.1 t
log3 = t log1.1
t = log3
log1.1
t &= 11.53
c)
100
10 = 1.04t
10 = 1.04 t
log10 = log1.04 t
1 = t log1.04
t =
1
log1.04
t &= 58.71
d) log5 = log1.08 t +2
log5 = (t + 2)log1.08
t + 2 =
t =
log5
log1.08
log5
log1.08 ! 2
t &= 18.91
e) log0.5 = log1.2 t !1
log0.5 = (t !1)log1.2
t !1 = log0.5
log1.2
t = log0.5
log1.2 +1
t &= !2.80
MHR • Advanced Functions 12 Solutions 676