Last Friday, We learned about the vertical and horizontal translations of a given function.
REVIEW: VERTICAL TRANSLATION
y=f(x)+k
y=f(x)-k
Where K is responsible for the vertical movement of the whole function.
EXAMPLE :
A. f(x)=x2
B. f(x)+2
SOLUTION:From parent function.The whole graph will move 2 points up.
You can also use table of values.
X | Y |
-2
-1
0
1
2 | ( -2)2 + 2 4+2 =6
( -1)2 + 2 1+2 =3
( 0)2 + 2 0+2 =2
(1)2 + 2 1+2 =3 (2)2 + 2 4+2 =6 |
C. f(x)-4
SOLUTION:From parent function.The whole graph will move 4 points down.
You can also use table of values.
X | Y |
-2
-1
0
1
2 | ( -2)2 -4 4-4 =0
( -1)2 -4 1-4 =-3
( 0)2 -4 0-4 =-4
(1)2 -4 1-4 =-3 (2)2 +-4 4-4 =0 |
NOTE: Given the equation of y=f(x)+ k , The x value does not change(x, y+ k ).
REVIEW: HORIZONTAL TRANSLATION
y=f(x-h)
y=f(x+h)
Where H is responsible for the horizontal movement of the whole function.
ALWAYS remember to read the H value as OPPOSITE.
B. f(x-4)
SOLUTION:From parent function.The whole graph will move 4 points to the right.
You can also use table of values.
X | Y |
3
4 5 | ( 3-4)2 -1^2 =1 ( 4-4)2 02 =0 ( 5-4)2 12 =1 |
C. f(x+3)
SOLUTION:From parent function.The whole graph will move 3 points to the left.
X | Y | |
-4 -3 -2 | ( -4+3)2 -12 =1 ( -3=3)2 02 =0 ( -2+3)2 12 =1 |
NOTE: Given the equation of y=f(x+ h) , The y value does not change(x+ h,y)
QUICK EXAMPLE
:COMBINATION OF VERTICAL AND HORIZONTAL TRANSLATION
graph y=(x+3)2 +4
SOLUTION:
Starting from parent function y=x2 , The whole graph will move 3 points to the left because of (x+3)2[remember we read h as opposite].From (x+3)2 , the graph will move four points down because of the k value +4 from the equation (x+3)2 + 4.
For your "Quick Example" question, did you mean to use the question: y=(x+3)^2 -4 rather than y=(x+3)^2 +4? If it was +4 you would move 4 points up instead of down. For some reason you have the right equation in red font on the chart, just not in the description.
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