d=1.3times square root of h

how high(to the nearest foot) would a platform have to be to see a distance of 15.5 miles?

4 answers

15.5= 1.3square root(h)
15.5/1.3=square root(h)
11.92=square root(h)
(11.92)^2=(square root(h))^2

h=142.16
so i don't do this?

15.5^2=1.3(square root(h)^2
240.25=1.3h
h=184.8
if you want to square both sides to get rid of the square root
you have to square the whole thing

so (1.3square root h)^2
which equals 1.69h instead of 1.3h

so h should = 142.16
great! thanks!!!