Lesson 3.2 Extra Practice Answers
1. a) Minimum
b) Maximum
c) Maximum
d) Minimum
6. a) $900 000
b) Maximum profit occurs when $20 000 is spent
on advertising.
c) $400 000
2. a) Minimum, 0
b) Minimum, ⫺11
c) Minimum, ⫺5
d) Maximum, 81
e) Minimum, 0
f ) Maximum, 14
7. $1739.58
3. a) R (x) ⫽ ⫺2x 2 ⫹ 12x, $18 000
b) R (x) ⫽ ⫺4x 2 ⫹ 16x, $16 000
c) R (x) ⫽ ⫺2x 2 ⫺ 8x, $8 000
d) R (x) ⫽ ⫺4.5x 2 ⫹ 1.7x, $482.30
4. a) ⫺4.31
b) 1.2
c) 1.8
d) ⫺1.69
9. Answers may vary. For example, the function is in
standard form, so to find the minimum, first find
the vertex. Completing the square would result in
fractions that are more difficult to calculate than
whole numbers. Since this function will factor,
putting the function in factored form and averaging
the zeros to find the x-coordinate of the vertex
would be possible; however, there would still be
fractions to work with. Using the graphing
calculator to graph the function, then using CALC
to find the minimum, would be the easiest method
for this function.
Copyright © 2008 by Thomson Nelson
5. a) P(x) ⫽ x 2 ⫹ 16x ⫺ 5, 8
b) P(x) ⫽ ⫺4x 2 ⫹ 24x ⫺ 1, 3
c) P(x) ⫽ ⫺2x 2 ⫹ 4x ⫺ 11, 1
d) P(x) ⫽ ⫺3x 2 ⫹ 24x ⫺ 24, 4
8. a) 79 m
b) 4 seconds
c) 15 metres
408
Functions 11: Lesson 3.2 Extra Practice Answers