math 135 ch 3 Flashcards
How do you determine the amount of possible roots/zeros in a polynomial?
By adding the total of all degrees
how many x-intercepts are there if the discriminant is > 0?
2 x-intercepts
how many x-intercepts are there if the discriminant is equal to 0?
1 x-intercept
how many x-intercepts are there if the discriminant is less that zero?
No x-intercepts
How do you find the discriminant?
b^2-4ac
How do you find the axis of symmetry?
Axis of symmetry is at the vertex, use -b/2a and f(-b/2a)
How do you know if an x-value is a lower bound?
The results of synthetic division show an alternation of positive and negative values.
How do you know if an x-value is an upper bound?
The results of synergies division show all positive values.
How do we know if an x-value is a zero/root to a polynomial?
- check by synthetic division where c=0
- r=c therefore the x-value is a factor of the polynomial
How to tell the number of possible positive real zeros in a polynomial?
The potential amount of positive real zeros in a polynomial is equal to or less than by an even number of the number of sign variations in the polynomial.
How to tell the potential number of negative real zeros of a polynomial.
The number is equal to or less than by an even number of the amount of sign changes in f(-x).
How to tell the number of potential negative real zeros of a polynomial?
The number is equal to or less than by an even number of the amount of sign changes in f(-x).
What is the conjugate zero theorem?
If a real zero of a polynomial is a conjugate, then so is its complex conjugate.
Explain the patterns of graph behaviors of polynomials
- x-values with a negative highest degree show that the ends are left down right up unless the coefficient is of negative value.
- values with a positive highest degree form a parabola and open down of the coefficient is of negative value.
- if the multiplicity is odd, the the graph cross the x-axis at the x-intercept.
- if the multiplicity is even, the the graph just touches the x-axis at the x-intercept.
How do you find limitations of a polynomial?
Look to highest degree of the polynomial for limitations in positive and negative infinity
Look to the constant for limitations towards zero, the limit is = to the constant.
How do you find the lead term of a factored polynomial?
Add all multiplicities, the sum is the lead term
What do the zeros of polynomials tell us?
A zero either reveals a vertical asymptote or a hole
What is the horizontal asymptote if the highest degree of the numerator is more than the degree of the denominator?
There is no HA
What is the horizontal asymptote if the highest degree of the numerator is less than the degree of the denominator?
y=0
What is the HA if the highest degree in the numerator and denominator are equal?
Divide thea coefficients of the num and denom to get HA
How do you find slant asymptote?
Oblique exists if the degree of the numerator is only higher than the degree of the denominator by 1. Do long division, ignore the remainder. The quotient is the location of the slant asymptote.
How do you format the vertical asymptotes?
As individual x-values and not in sets.