To find the zeros of this function, we must first set the entire function equal to 0
f(x) = x² - 2x - 15 = 0
Since this is a quadratic function, we must use the quadratic formula, which is:

Let's assign a, b, and c using our first function
x² means a = 1 (because it could be written as 1x²)
-2x means b = -2
-15 means c = -15
Now let's plug those in:

which simplifies to:

Simplified further:


And divide it by the 2 on the bottom gives us:

2+4 = 6
2-4 = -2
So the zeros of this function are
-2 and
6
1/2 is a fraction so it is 5
<u>Step-by-step explanation:</u>
To prove:

Identities used:
......(1)
........(2)
.......(3)
Taking the LHS:

Using identity 1:

Using identities 2 and 3:

As, LHS = RHS
Hence proved
1. (16,25)-(24,5) the interval it falls from is 25 mph to 5 mph or it decreased by 20 mph.
2. From D (24,5) to E (28,45). The interval of time from point D to point E is 5 mph to 45 mph. or it increased by 40 mph.
3. From B (6,25) to C (16,25) and the constant rate is 25 MPH.
I'm not 100% sure about the everything.