What is the domain of the function y=3 in x graphed below?
Domain is x>0, ln (0) is undefined and there is no negative ln.
Answer is (1) 160 km in 2 hours and
(2) 16 miles in 12 minutes.
Step by step.
80 km / 1 hour = x km /2 hours
Cross multiply =
x = 160
The second one requires a little more math. Because we are looking at how far in minutes, we change the rate of 80km in 1 hour to 80 km in 60 minutes.
80 km / 60 = x / 12
Cross multiply
12x = 960
Solve for x by dividing both sides by 12
X = 16
I did the math on a print screen to explain the cross multiply.