Which shows a difference of squares?
1 answer:
A difference of squares must be a binomial, so we want two terms. This rules out the third and fourth options.
If we look at the first two, we must check that both terms are perfect squares.
Look at the first one: is a perfect square (it's
), but
is not a perfect square, because 10 is not a perfect square.
On the other hand, if we look at the second option, is the square of
, and
is clearly the square of
. So, this is the difference of two squares.
You might be interested in
Answer:
• multiplied by 4p: (x -h)² +4pk = 0
• zeros for k > 0: none
• zeros for k = 0: one
• zeros for k < 0: two
Step-by-step explanation:
a) Multiplying by 4p removes the 1/(4p) factor from the squared term, but adds a factor of 4p to the k term. (It has no effect on the subsequent questions or answers, so we wonder why we're doing this.) The result is ...
(x -h)² +4pk = 0
__
b) The value of k is the vertical location of the vertex of the parabola with respect to the x-axis. The parabola opens upward, so for k > 0, the parabola does not cross the x-axis, and the number of real zeros is zero. (There are two complex zeros.)
__
c) As in part b, the value of k defines the vertex location. When it is zero, the vertex of the parabola is on the x-axis, so there is one real zero (It is considered to have multiplicity 2.)
__
d) As in part b, the value of k defines the vertex location. When it is negative, the vertex of the parabola is below the x-axis. Since the parabola opens upward, both branches will cross the x-axis, resulting in two real zeros.
_____
The attached graph shows a parabola with p=1/4 and h=2. The values shown for k are +1, 0, and -1. The coordinates of the real zeros are shown.
