text: Focus 1 (F1) is at (-150),0 and F2 is at (150,0)\nThe ship is at a point P(x,75)\nThe distance F1P is [(x+150)^2 +75^2)]^0.5\nThe distance F2P is [(x- 150)^2 +75^2)]^0.5\n\nThe difference between these two distances is 186,000*.0001=\n18.6 miles. Therefore a = 9.3 and a^2=86.49\n\nc=1/2 F1F2=150\nb^2= c^2-a^2=22500-86.49=22413.51\n\nThe equation of the hyberbola is x^2/86.49-y^2/22,413.51=1\nTo find x we use the equation:\n[(x+150)^2 +75^2)]^0.5 -  [(x- 150)^2 +75^2)]^0.5 = 18.6\n[x^2+300x+ 28125]^0.5-[x^2 -300x +28125]^.5=18.6\nx^2+300x+ 28125= 18.6^2+37.2[x^2 -300x +28125]^.5 +x^2 -300x +28125\n600x-345.96 = 37.2[x^2 -300x +28125]^.5\n360000x^2 -691.92x +119,688.32 = 1383.84x^2 -41515.2x+38,920,500\n358,616.16x^2+40,823.28x -38,800,812\nx^2 + .1138x - 108.196=0\nx= [-.1138 + sqrt(.1138^2 +432.784)]/2 = 10.35