chapter 4

This week we started Chapter Four. This chapter has to do with domain and range. Anyway, here we go with the blogging and the learning and what not. I will be going over finding the domain and range of a polynomial.

-Domain: the interval of x values where the graph exists.

-Range: the interval of y values where the graph exists

-Zeros, x-int, root- set=0 solve for x

-To be a function the graph must pass the vertical line test.

-If given points the domain is the list of all x-values and range is a list of all y-values in { }

To find domain and range:

Polynomials

Domain: (-infinity, infinity) ALWAYS

Range: odd (-infinity, infinity) always x^2 (-b/2a, infinity) if parabola opens up or (-infinity, -b/2a) if parabola opens down.

Example:

Find the domain and range of the following
F(x)=7x^3+4x^2-18

As previously stated, the domain of a polynomial is always (-infinity, infinity)

Since the largest exponent is odd, the range is (-infinity, infinity).

Example 2:

Find the domain and range of the following
F(x)=7x^2-28

The domain is (-infinity, infinity)

The parabola opens upwards therefore the range will be (-b/2a,infinity).

The range is [2, infinity)

Good luck on the test everyone (:
--Sarah