How can you tell from the standard form whether a quadratic function has exactly one zero

The discriminant equals zero.

Explanation:

The standard form of a quadratic equation is

ax² + bx + c = 0

The solution is the familiar quadratic formula

The term b² -4ac is the discriminant (D).

D tells you the number of roots.

If D = 0, the solution to the equation becomes

If D = 0, there is exactly one zero.

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Example:

Find the zeroes of

f(x) = x² - 2x + 1

x = 1

The graph is a parabola with its vertex touching the x-axis at x = 1.

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !