Answer:
Step-by-step explanation:
The rate of change of the function f(x) from point 
to point 
can be calculated using formula
Given
From the graph of the function
So, the rate of change is
Answer:
y = x² - 4x - 21
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (2, - 25), thus
y = a(x - 2)² - 25
To find a substitute (7, 0) into the equation
0 = a(7 - 2)² - 25 = a(5)² - 25 = 25a - 25 ( add 25 from both sides )
25a = 25 ( divide both sides by 25
a = 1, thus
y = (x - 2)² - 25 ← in vertex form
Expand and simplify
y = x² - 4x + 4 - 25
y = x² - 4x - 21 ← in standard form
Answer:
(a) Number of inches that have burned from the candle since it was lit is (1.1t) inches
(b) The remaining length of the candle is (16 - 1.1t) inches
Step-by-step explanation:
(a). Length of candle before it was lit = 16 inches
Constant rate at which at which candle burns = 1.1 inches per hour
Let t represent the number of hours that have elapsed since the candle was lit
In 1 hour, 1.1 inches of the candle burned
Therefore, in t hours, (1.1t) inches of the candle would have burned since the candle was lit
(b) Remaining length of candle = length of candle before it was lit - length of candle that have burned = 16 inches - 1.1t inches = (16 - 1.1t) inches
