00:01
So the first thing we have to do is factor out this polynomial.
00:05
So if we factor out a negative x, what we're left with is 2x squared, 2x squared plus x, and then minus 1.
00:18
And so we want to make this easier to factor.
00:22
So we're going to multiply this 2 by 1.
00:24
So this is the ac method.
00:26
So we have negative x, and then we're going to change this to x squared plus x minus 2.
00:33
And so this becomes easier to factor because we know that two multiple two numbers that add up to negative one or two numbers that multiply to negative two by add up to one are positive two and negative one.
00:46
So we have this negative x and then x plus two and then x minus one.
00:53
But remember since we since we multiplied by two, we now have to divide by two for both.
00:57
So we have this divide by two here.
01:00
It's divide by two here.
01:01
And so we're left with this, negative x times x plus 1, and then 2x minus 1.
01:10
So now we have, we have our zeros are 0, negative 1, and then if we set 2x minus 1 to be equal to 0, we have x is equal to 1 half.
01:25
And so now we know our 0s, all of these have a multiplicity of 1.
01:29
And so now we can determine our n behavior.
01:31
So as x tends to positive infinity, well, let's see here, we have negative infinity times positive infinity times positive infinity...