We notice that the given relation represents a complete
square. We'll use the special products to factor the
expression.
We'll recall that a binomial raised to square
is:
(a-b)^2 = a^2 - 2ab +
b^2
We'll identify a and b:
a
= 6 and b = -(y+y^2)
2ab =
-12(y+y^2)
Therefore, we can re-write the given expression
as:
E(x) = 36-12(y+y^2)+(y+y^2)^2 = (6 - y -
y^2)^2
We'll verify if the quadratic within brackets has
real roots.
y^2 + y - 6 = 0
y1
= [-1+sqrt(1+24)]/2
y1 =
(-1+5)/2
y1 = 2
y2 =
(-1-5)/2
y2 = -6/2
y2 =
-3
Therefore, the quadratic can be written as a product of
linear factors:
y^2 + y - 6 =
(y-y1)(y-y2)
y^2 + y - 6 =
(y-2)(y+3)
Therefore, the complete factorized
expression is: E(x)=[(y-2)(y+3)]^2
No comments:
Post a Comment