If you stand on a ship in a calm sea, then your height x (in ft) above sea level is related to the farthest distance y (in mi) that you can see by the equation y = 1.5x + x 5280 2 .

Question

If you stand on a ship in a calm sea, then your height x (in ft) above sea level is related to the farthest distance y (in mi) that you can see by the equation

y =	1.5x +	x
5280
	2

.

(a) Graph the equation for 0 ≤ x ≤ 100.

(b) How high up do you have to be to be able to see 5 mi? (Round your answer to the nearest whole number.)

 ft

Answer 1

Assuming your equation read y=sqrt(1.5x + (x/5280)²) then your could enter in different values for for x such as 20 and 40, to find at least 2 points and compare with the provided graphs, you could plug the equation into a graphing calculator. The correct answer is the top left graph.

Since we want to solve for x (how high up we are) we would substitute 5 for our y value, so our equation would look like 5=sqrt(1.5x+(x/5280)²) which would give us an x value of 16.66, rounded to the nearest whole number, 17feet.