F(x) is continuous for all x.
Pick a point and show that f(x) is either negative or positive. Pick another point and show that f(x) is negative, if positive, or positive, if negative.
At x = 30, f(30) - 1000 = 900 + 10sin(30) - 1000 ≤ 0
Now, show at another point f(x) - 1000 is positive, and hence, there would be root between 30 and such point.
Let's pick 40.
At x = 40, f(40) - 1000 = 1600 + 10sin(40) - 1000 ≥ 0
Since f(x) - 1000 is continuous, there lies a root between 30 and 40, and hence, 30 ≤ c ≤ 40
Answer:
Boat traveled 553.24 feet towards the lighthouse.
Step-by-step explanation:
In the figure attached AB is the light house of height 200 feet.
Angle of depression of the boat from the top of a lighthouse = angle of elevation of the lighthouse from the boat = 14°52'
so 1' =
degree
so angle of elevation at point C = 14 + 
So angle of elevation from C = (14 + 0.87) = 14.87°
Similarly, when boat arrives at point D angle of elevation = 45°10' = 45 +
= 45.17°
Now we have to calculate the distance CD, traveled by the boat.
In ΔABC
tan14.87 = 
0.2655 = 
BC = 
BC = 753.239 feet
Similarly in ΔABD
tan45.17 = 
1 = 
BD = 200 feet
So distance CD = BC - BD
CD = 753.239 - 200
= 553.24 feet
Therefore, Boat traveled 553.24 feet towards the lighthouse.
General exponential equation
y = A(1+r)^x
where
A = initial value
r = rate increase (+) or decrease (-)
x = time period of the change
y = projected value
y = 300(1.05)^x
in this problem, x = years after 2017
we want to find an x that makes the value more than or equal to 650
650 <= 300(1.05)^x