The graph of <span>y=-0.5 sqrt (x-3)+2
Df= {x/x-3>=0}
Df= [3, + infinity[
derivative of f(x)
f'(x)= -0.5 x 2 /</span>sqrt (x-3)= - 1/sqrt (x-3) <0, f is a decreasing function for all x in the Df
limf(x)=2 x--------->3, limf(x)=-infinity, x--------->+infinity
look at the graph
Let the boat speed in still water be b.
Let the current speed be c.
The speed going upstream is 20/4 = 5 mph.
The speed going downstream is 32/4 = 8 mph.
b - c = 5 ........(1)
b + c = 8 .......(2)
Adding equations (1) and (2) we get:
2b = 13
b = 13/2 = 6.5
Plugging in the value for b into equation (1) we find c = 1.5.
The boat speed in still water is 6.5 mph and the current speed is 1.5 mph.
Answer:
7
Step-by-step explanation:
<span>Let the nickels be x and the dimes be y
x + y = 24
5x + 10y = 185
5x + 5y = 120
5y = 65
y=13
x=11
Answer: 11 nickels and 5 dimes</span>