SOLUTION: f(x)=x^2+4x-45 Does the graph of f open up or down. What is the vertex (h,k) of f What is the axis of symmetry What are the intercepts What is the domain of f What is the ran

Algebra ->  Rational-functions -> SOLUTION: f(x)=x^2+4x-45 Does the graph of f open up or down. What is the vertex (h,k) of f What is the axis of symmetry What are the intercepts What is the domain of f What is the ran      Log On


   

Question 238497: f(x)=x^2+4x-45
Does the graph of f open up or down.
What is the vertex (h,k) of f
What is the axis of symmetry
What are the intercepts
What is the domain of f
What is the range of f
on what interval f is decreasing
On what interval f is increasing
Answer by solver91311(24713) About Me  (Show Source):
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is a parabola of the form



The lead coefficient is positive so the parabola opens upward.

The -coordinate of the vertex is given by

Then obviously the -coordinate of the vertex must be

The axis of symmetry is the vertical line

The -intercepts, if any exist, are the values of that satisfy

The -intercept is found by evaluating

The domain of any polynomial function is all real numbers. The range of a quadratic polynomial in the form



that opens upward is

A parabola that opens upward is increasing to the right of the vertex, that is to say the interval [)

Quite obviously the decreasing interval is (]

John