Simplify the rational expression. Use factoring, and assume all variable expressions represent positive real numbers.
-A formula for calculating the distance, d, one can see from an airplane to the horizon on a clear day is $$\mathrm { d } = 1.22 \mathrm { x } ^ { 1 / 2 }$$ , where x is the altitude of the plane in feet and d is given in miles. How far can one see in a plane flying at 20,000 feet? Round your answer to the nearest tenth mile, if necessary.
A) 172.5 mi
B) 12,200 mi
C) 156.2 mi
D) 1220 mi

Question

Quizplus · Accepted Answer

To find the distance one can see from an airplane to the horizon, substitute $x = 20,000$ feet into the given formula $d = 1.22x^{1/2}$. Calculating gives $d = 1.22 \times (20,000)^{1/2} = 1.22 \times 141.4 \approx 172.5$ miles.

Simplify the Rational Expression d=1.22x1/2\mathrm { d } = 1.22 \mathrm { x } ^ { 1 / 2 }d=1.22x1/2

Simplify the Rational Expression $\mathrm { d } = 1.22 \mathrm { x } ^ { 1 / 2 }$