Lesson Summary 5 March

Steps (shortcut) to sketching ><

1) if a is positive, the graph has a min turning point
 if a is negative, the graph has a max turning point

2) c refers to the y intercept of the graph

3) D, the discriminant, affects the nature of the roots
if D is greater than zero, the roots are real and different
if D is equal to zero, the roots are real and similar
if D is less than zero, the roots are imaginary

4) in completing the square [ (x+h)^2+k ], the turning point is (h,k)

eg. y=x^2-3x+5
1) is a graph with a min turning point
2) has a y intercept of 5
3) is imaginary (D=-11)
4) has a turning point of (1.5, 2.75)

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Difference between plotting and sketching

                     Drawing/Plotting                 SKetching
Scale                       Y                               N
Accuracy                  Y                               N
Plotting Points            Y                               N
Label                       Y                               Y
Construction lines       Y                               N