Page 36 - Calculus Workbook For Dummies

20 Part I: Pre-Calculus Review

Q. If f x = 3 x - 4 x + 8, what does f a + bh Q. For the line g x = - 4 x, what’s the slope
2
5
^
^ h
^ h
equal? and what’s the y-intercept?
A. 3 a + 6 ab + 3 b - 4 a - 4 b + 8 A. The slope is –4 and the y-intercept is 5.
2
2
Does y = mx + b ring a bell? It better!
2
f x = 3 x - 4 x + 8
^ h
2
b +
f a + b = ^h 3 a + b - ^h 4 a + h 8
^
2
2
= 3 _ a + 2 ab + b i - 4 a - 4 b + 8
2
2
= 3 a + 6 ab + 3 b - 4 a - 4 b + 8

1. Which of the four relations shown in the 2. If the slope of line l is 3,
figure represent functions and why? (A
relation, by the way, is any collection of a. What’s the slope of a line parallel to l?
points on the x-y coordinate system.) b. What’s the slope of a line perpendicular
to l?
y y
Solve It

x x

2
a. y = |x| b. x + y = 9
2
y y

x x

3
2
c. x = y - 5y + 10 d. y = sinx
Solve It