Answer:
True
Step-by-step explanation:
(x + 4)² = (x + 4) (x + 4)
x² + 4² = x² + 16
Answer: Crickets make 172 chirps/min at 80 degrees Fahrenheit
Step-by-step explanation:
Step 1
Using the point slope formulae for Linear functions , we have that
y - y1 = m(x - x1)
where x and y are two points representing the temperature and chirps /min respectively
And
m= slope
Step 2 : Finding the slope , m
where x1=60
y1=92
x2= 75
y2=152
m= (y2-y1)/ (x2-x1)
= (152- 92)/(75-60)
=60/15 =4
Bringing down the point/slope formula and imputing the known values to find our equation to show the relationship cricket make per minute and the temperature
y - y1 = m(x - x1)
y - 92= 4(x - 60)
y - 92 = 4x -240
y = 4x - 240 + 92
y = 4x - 148
Step 3
To find the number of chirps be per minute (y) if the temperature is 80 degrees Fahrenheit( x)
y = 4(80) - 160
y = 320 - 148
y = 172 chirps/min at 80 degrees Fahrenheit
To get the vertex of the parabola we proceed as follows;
y=-7(x-4)^2-5
The above can be written as:
y=-7x^2+56x-117
The values of a,b and c are:
a=-7, b=56 and c=-117
x=-b/(2a)
x=-56/(-7*2)=4
but;
y=-7x^2+56x-117
y=-7(4)^2+56(4)-117
y=-5
Thus;
x=4 and y=-5
The vertex will be at point (4,-5)