<span>4x-2y=-1
</span><span>Slope = 2
x-intercept = -1/4
y-intercept = 1/2
</span><span>-4x+4y=-2
</span><span>Slope = 1
x-intercept = 1/2
y-intercept = 1/-2 </span>
The surface area would be 166.
A fake link ........................
From the astronaut to the horizon is a tangent line to the curvature of the earth. And from that point on the horizon to the center of the earth is at a right angle to the tangent and is equal to the radius of the earth...so we can say
cosα=r/(r+h) where r is the radius of the earth and h is the height above the surface of the earth...
α=arccos(r/(r+h))
now tanα=d/r where d is the distance from the astronaut to the point on the horizon so:
tan(arccos(r/(r+h))=d/r
d=rtan(arccos(r/(r+h))) and using r≈4000 and h=50 we get:
d=4000tan(arccos(4000/(4050)))
d≈634.42mi
d≈634 mi (to nearest mile)
