A ray is a line that has a begining point, but no end point
a ray is 1 dimentional, it only goes one direction, left and right
a plane is 2 dimentional and extends indefinitely
it goes left and right and up and down
think of it like this
you have a piece of paper with no height
you draw a line starting at a point on the paper and it goes infinitely in the other direction
the paper is a plane, the line on it that has a starting point is the ray
X=a
f(a)=5(a^0)+4a^-3 a^0=1
=5(1)+4/a^3
=5+4/(a^3)
-3^4 (Three to the Fourth power)