they look like this 0 zeros. what are zeros? zeros are what x equals or where your graph touches...

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THEY LOOK LIKE THIS 0 Zeros

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Page 1: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

THEY LOOK LIKE THIS 0

Zeros

Page 2: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

What are zeros?

Zeros are what x equals

OR

Where your graph touches the x-axis

Page 3: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

How to Find Zeros

1.  If you have a graph, look at it.

Wherever the graph crosses the x-axis, those are your zeros.

Page 4: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

2. If you have no graph and a simple equation like this:

-2x+4=0

Just solve.

Page 5: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

-2x+4=0       -4

-2x=-4                /-2

x=-4/-2x=2

Page 6: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

3. If you have a quadratic equation like this:

x = -2x2 - 6x + 8 = 0

No need to fear.

Just factor.

Page 7: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

x = -2x2 - 6x + 8 = 0

becomes

(-2x-7)(x-1)=0

Set each one equal to 0 and solve

Page 8: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

-2x-7=0         +7

-2x=7           /-2

x=7/-2

x-1=0      +1

x=1

x=7/-2, x=1

Page 9: THEY LOOK LIKE THIS  0 Zeros. What are zeros? Zeros are what x equals OR Where your graph touches the x-axis

What if factoring doesn't work?!?!

Don't worry. It's okay.

Use the quadratic formula.

-b +/- (square root)b2-4ac/2a