Question

How do I find the x and y intercepts of y = x(x - 4)

Answer 1

to find x-intercept,put y=0,
to find y-intercept ,put x=0
in the equation
y = x(x - 4)

Answer 2

Thanks!

Answer 3

So y = -4?

Answer 4

Hello?

Answer 5

y = x(x - 4)

Y Intercept: [0,b]
y = 0(0-4)
y = 0(0)+(0(-4))
y = 0 + 0
y = 0

y intercept: (0,0)

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X Intercept: [a,0]

0 = x(x-4)*
1.) x=0
2.) (x-4)=0
x = 4

x intercept/s: (4,0) and (0,0)

Note. Use the zero factor/product property to solve the above:
*Zero factor property: If ab=0, then either a=0 or b=0*

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Notes.

The Fundamental Theorem of Algebra: If p(x) is a polynomial of degree n then p(x) will have exactly n zeroes, some of which may repeat.

The Factor Theorem: "A polynomial equation f(x) has a factor (x-k) if and only if f(k) = 0."

Quadratic Equations:
*Zero factor property: If ab=0, then either a=0 or b=0*

Factor Theorem of Algebra: http://en.wikipedia.org/wiki/Root-finding_algorithm
Root-Finding Algorithm: http://en.wikipedia.org/wiki/Root-finding_algorithm
Quadratic Equations and Zero Factor Property: http://tutorial.math.lamar.edu/Classes/Alg/SolveQuadraticEqnsI.aspx