Answer: Choice B) -3
------------------------------------------------------
Work Shown:
f(x) = (x+2)/2
f(-8) = (-8+2)/2 ... replace every x with -8; use PEMDAS
f(-8) = (-6)/2
f(-8) = -3
Answer:
- vertical scaling by a factor of 1/3 (compression)
- reflection over the y-axis
- horizontal scaling by a factor of 3 (expansion)
- translation left 1 unit
- translation up 3 units
Step-by-step explanation:
These are the transformations of interest:
g(x) = k·f(x) . . . . . vertical scaling (expansion) by a factor of k
g(x) = f(x) +k . . . . vertical translation by k units (upward)
g(x) = f(x/k) . . . . . horizontal expansion by a factor of k. When k < 0, the function is also reflected over the y-axis
g(x) = f(x-k) . . . . . horizontal translation to the right by k units
__
Here, we have ...
g(x) = 1/3f(-1/3(x+1)) +3
The vertical and horizontal transformations can be applied in either order, since neither affects the other. If we work left-to-right through the expression for g(x), we can see these transformations have been applied:
- vertical scaling by a factor of 1/3 (compression) . . . 1/3f(x)
- reflection over the y-axis . . . 1/3f(-x)
- horizontal scaling by a factor of 3 (expansion) . . . 1/3f(-1/3x)
- translation left 1 unit . . . 1/3f(-1/3(x+1))
- translation up 3 units . . . 1/3f(-1/3(x+1)) +3
_____
<em>Additional comment</em>
The "working" is a matter of matching the form of g(x) to the forms of the different transformations. It is a pattern-matching problem.
The horizontal transformations could also be described as ...
- translation right 1/3 unit . . . f(x -1/3)
- reflection over y and expansion by a factor of 3 . . . f(-1/3x -1/3)
The initial translation in this scenario would be reflected to a translation left 1/3 unit, then the horizontal expansion would turn that into a translation left 1 unit, as described above. Order matters.
Answer:
(2, - 3 )
Step-by-step explanation:
Given the 2 equations
2x - 3y = 13 → (1)
x + 2y = - 4 → (2)
Rearrange (2) expressing x in terms of y by subtracting 2y from both sides
x = - 4 - 2y → (3)
Substitute x = - 4 - 2y into (1)
2(- 4 - 2y) - 3y = 13 ← distribute and simplify left side
- 8 - 4y - 3y = 13
- 8 - 7y = 13 ( add 8 to both sides )
- 7y = 21 ( divide both sides by - 7 )
y = - 3
Substitute y = - 3 into (3) for corresponding value of x
x = - 4 - 2(- 3) = - 4 + 6 = 2
Solution is (2, - 3 )