Unit 5c Graphing Quadratics

Unit 5cGraphing

Quadratics

Transformations of Quadraticsin Vertex Form

Vertex Form for Quadratics

f(x) = a(x – h)2

+ v

f(x) = a(x – h)2 + vIf a is NEGATIVE

then the graph reflects across the x-axis.

If |a| is less than 1, the graph SHRINKS.

If |a| is greater than 1 the graph STRETCHES.

h is TRICKY!If h is POSITIVE then the graph moves LEFT.If h is NEGATIVE then the graph moves RIGHT.

Axis of Symmetry: x = h

Special CaseIf x is NEGATIVE inside then the graph reflects across the y-axis and h takes the sign you see.

If k is POSITIVE then the graph moves UP.

If k is NEGATIVE then the graph moves DOWN.

Vertex: (h, k)

NEGATIVE on the INside, what does this cause the graph to do?

Reflect across the y(h will be the same as it’s sign)

2f x a x h k

NEGATIVE on the OUTside, what does this cause the graph to do?

Reflect across the x

2f x a x h v

Number less than 1 outside, what does this cause the graph to do?

Shrink by 3/4

23

4f x x h v

Number greater than 1 outside, what does this cause the graph to do?

Stretch by 8

28f x x h v

Add on the inside, what does this cause the graph to do?

Move LEFT 2

22f x a x v

Subtract on the inside, what does this cause the graph to do?

Move RIGHT 7

27f x a x v

Subtract on the outside, what does this cause the graph to do?

2 3f x a x h

Move Down 3

Add on the outside, what does this cause the graph to do?

Move Up 5

2 5f x a x h

DESCRIBE THE TRANSFORMATI

ON

21( ) ( 3) 54f x x 1 4

35

Shrink

rightup

3

79

reflect acrossx axisstretch byleftdown

2( ) 3 7 9f x x

Write the equation of

the pink graph

2 2f x x

2 Parent Graphf x x

23f x x

2 Parent Graphf x x

2 4f x x

2 Parent Graphf x x

2 Parent Graphf x x

2f x x

24f x x

2 Parent Graphf x x

23f x x

2 Parent Graphf x x

Class Work/HomeworkVertex Form of a

Quadratic WS