Answer:
A. Between 3.0 and 3.5 and between 4.0 and 4.5
Step-by-step explanation:
The zeroes of a function occur whenever a value of x returns zero. To predict where the zeroes lie, determine the interval(s) where the function crosses the x-axis. This occurs when either goes from a negative value to a positive value or vice versa.
From and , the y-values go from 4.0 (positive) to -0.2 (negative), respectively. Therefore, there must be a zero in this interval.
From and , the y-values go from -0.8 (negative) to 0.1 (positive), respectively. Therefore, there must also be a zero in this interval.
Thus, the zeros of this function occur between 3.0 and 3.5 and between 4.0 and 4.5, leading to answer choice A.
X^2 - 8x-9=0
D = b^2- 4*a*c = 64- 4* (-9) = 64+36=100 =10^2
X1 = (8-10)/2 = -1
X2= (8+10)/2= 9
Smaller x = -2/5
Larger x = 5
A) A=500(1+0.015)^t
b)800=500(1.015)^t
800/500=1.015^t
t=log(800/500)/log(1.015)
t=31.6 years