Question

17.

An object is shot upward and it moves in a parabola path. The path is given by the
quadratic function f(x) = 30x - 5x².
(a) Express it in the form of a(x - p)² + q where a, p and q are constant.
(b) Find the maximum height of the object.

Answer 1

A

Explanation:

"Changing the measurement unit" is the correct answer because it's like transforming a measurement into a different language or currency, but keeping the meaning or value intact. When you convert from feet to inches, you're essentially translating the measurement into a smaller unit (inches) while preserving the original quantity or value. It's similar to how you can express the same distance or length in different units, like converting from miles to kilometers or from pounds to kilograms. It's like speaking the measurement's language in a different dialect or using a different currency for the same value.

Answer 2

(a) To express the quadratic function in the form of a(x - p)² + q, we first need to complete the square:

f(x) = 30x - 5x²

= -5(x² - 6x)

= -5(x² - 6x + 9 - 9)

= -5[(x - 3)² - 9]

= -5(x - 3)² + 45

Therefore, the function in the form of a(x - p)² + q is f(x) = -5(x - 3)² + 45, where a = -5, p = 3, and q = 45.

(b) The maximum height of the object occurs at the vertex of the parabola, which is at x = p = 3. Therefore, to find the maximum height, we plug x = 3 into the equation:

f(3) = -5(3 - 3)² + 45

= 45

So the maximum height of the object is 45 units.

Hope this helps!