1. Quadratic Graphs y = x 2 + 2x - 2 x-3-2012 x2x2 2x -2 y Remember that -2 in the equation is the intercept so it will run through -2 -2 -2

2. Quadratic Graphs y = x 2 + 2x - 2 x-3-2012 x2x2 2x -2 y 94 1 0 1 4 Note: - X - = + So -2 2 = -2 X -2 = 4 Use it to find the values of x 2 Now let’s multiply each value of x by 2 to find the values of 2x + X - = - so 2 X -3 =-6 -6 -4 -2 0 2 4

3. To find the values of y, we must sum all the values of x 2, 2x and - 2. Be careful with the negative signs. Quadratic Graphs y = x 2 + 2x - 2 x-3-2012 x2x2 941014 2x-6-4-2024 y 1 -3-216

4. Quadratic Graphs y = x 2 + 2x - 2 x-3-2012 x2x2 941014 2x-6-4-2024 y1 -3-216 Plot the values of x and y on the grid and join the points with smooth curve. y = x 2 + 2x - 2

5. Quadratic Graphs More negative values y = x 2 – 3x - 2 x01234 x2x2 -3x -2 y Remember that -2 in the equation is the intercept so it will run through -2 -2 -2 -2 -2 -2 N o t e : - X - = + S o - 1 2 = - 1 X - 1 = 1 U s e i t t o f i n d t h e v a l u e s o f x 2. T h e s e a r e j u s t t h e o r d i n a r y s q u a r e n u m b e r s. 1 0 1 4 9 16

6. Quadratic Graphs More negative values y = x 2 – 3x - 2 x01234 x2x2 1014916 -3x -2 y Multiply each value of x by -3. - X - = + - X + = - T o f i n d t h e v a l u e s o f y, w e m u s t s u m a l l t h e v a l u e s o f x 2, 2 x a n d - 2. B e c a r e f u l w i t h n e g a t i v e s i g n s.. 3 0 -3 -6 -9 -12 2 -2 -4 -22

7. Quadratic Graphs More negative values y = x 2 – 3x - 2 x01234 x2x2 1014916 -3x30-3-6-9-12 -2 y2 -4 -22 Plot the values of x and y on the grid and join the points with smooth curve y = x 2 – 3x - 2