(Real functions and equations) How to select points for a graph.

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SUMMARY

This discussion focuses on selecting points for graphing quadratic, square-root, and inverse variation functions. Key methods include identifying base points for each function type, such as (0,0), (1,1), and (2,4) for quadratic functions. For square-root functions, the points are derived from the equation $$f(x)=a\sqrt{g(x)}+b$$ by setting $$g(x')=n^2$$, where $$n$$ is a natural number including zero. The discussion also clarifies the transformation of points using the vertex form $$f(x)=a(x-h)^2+k$$ and emphasizes the importance of the axis of symmetry in graphing.

PREREQUISITES
  • Understanding of quadratic functions and their properties
  • Familiarity with square-root functions and their graphing techniques
  • Knowledge of inverse variation and its mathematical representation
  • Basic grasp of function transformations and vertex form
NEXT STEPS
  • Study the properties of quadratic functions and practice identifying vertices and intercepts
  • Learn how to graph square-root functions using the transformation method
  • Explore inverse variation and its applications in real-world scenarios
  • Practice plotting points for various functions using the vertex form $$f(x)=a(x-h)^2+k$$
USEFUL FOR

Students, educators, and anyone involved in mathematics who seeks to improve their skills in graphing functions, particularly quadratic and square-root functions.

Kyriakos1
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When I am given a function quadratic, square-root and inverse variation I am often uncertain as to how to select my points to graph the function. Usually I can find my vertex easily enough and y and x intercepts if any but otherwise I don't know how to select my points. Are there base points for each function? Such as (0,0), (1,1), (4,2), (8,2.8) for a function of square-root or (0,0), (1,1), (2,4), (-1,1), (-2,4) for a quadratic function.
 
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If I am given a function of the form:

$$f(x)=a\sqrt{g(x)}+b$$

Then, I will find $x=x'$ such that:

$$g(x')=n^2$$ where $$n\in\mathbb{N_0}$$

Then I plot the points:

$$(x,y)=(x',an+b)$$

If I am given a function of the form:

$$f(x)=a(x-h)^2+k$$

I let $$x=h+n$$ where $$n\in\mathbb{N_0}$$, and then for each point, reflect it across the axis of symmetry. You will get the set of points:

$$(x,y)=(h\pm n,an^2+k)$$
 
I thank you for answering and I do not mean to sound ungrateful but I don't really understand your explanation. I do not understand these symbols: n ∈ N 0 x′.
Also I have learned the square root-function as f(x)=a\sqrt{b(x-h)} + k and am unsure how to use f(x)=ag(x)−−−−√+b. Perhaps you can dumb it down a notch.
 
The statement $$n\in\mathbb{N_0}$$ means that n is a natural number including zero, that is:

$$n\in\{0,1,2,3,\cdots\}$$

If you are given:

$$f(x)=a\sqrt{b(x-h)}+k$$

then set:

$$b(x-h)=n^2\implies x=\frac{n^2}{b}+h$$

which generates the points:

$$\left(\frac{n^2}{b}+h,an+k\right)$$
 

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