Answer:
y = 20*4^x
Step-by-step explanation:
to find the value of the constants a and b, we just need to use the points given in the equation and solve the system of equations:
point (0,20): x = 0 and y = 20:
20 = a*b^0 = a*1 = a
a = 20
point (2,320): x = 2 and y = 320
320 = 20 * b^2
b^2 = 16
|b| = 4
b = 4 or b = -4
So we have two exponencial equations that pass through these points:
y = 20*4^x and y = 20*(-4)^x
As the questions asks for just one equation, we can answer y = 20*4^x
372
The number 3 is in the hundreds place.
Look to the number immediately to the right.
We know that 7 is bigger than 3.
So, we add 1 to 3 and the rest become 0.
Answer: 400
Answer:
a=2.5
Step-by-step explanation:
3a-2.4=5.1 Add the like terms ( plus 2.4 cancels out -2.4)
+2.4 +2.4
3a=7.5 Now divide by 3
/3 /3
a=2.5
Answer:
a) No. t < 0 is not part of the useful domain of the function
b) 2.0 seconds
Step-by-step explanation:
a) A graph of the function is shown below. It shows t-intercepts at t=-0.25 and t=2.0. We presume that t is measured forward from some event such as the ball being thrown or hit. The model's predicted ball location has no meaning prior to that event, when values of t are negative.
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b) It is convenient to use a graphing calculator to find the t-intercepts. Or, the equation can be solved for h=0 any of several ways algebraically. One is by factoring.
h = 0 = -16t² +28t +8 . . . . . . . . . . . . the ball hits the ground when h = 0
0 = -4(4t² -7t -2) = -4(4t +1)(t -2)
This has t-intercepts where the factors are zero, at t=-1/4 and t=2.
The ball will hit the ground after 2 seconds.