By letting

we get derivatives


a) Substitute these into the differential equation. After a lot of simplification, the equation reduces to

Examine the lowest degree term
, which gives rise to the indicial equation,

with roots at r = 0 and r = 4/5.
b) The recurrence for the coefficients
is

so that with r = 4/5, the coefficients are governed by

c) Starting with
, we find


so that the first three terms of the solution are

Answer:
A and B
Step-by-step explanation:
Answer:
Skew lines
Step-by-step explanation:
Skew lines are two straight lines in three dimensional space that are neither parallel nor do they intersect Examples of skew lines are the front sidewalk and a line that goes along one of the top edges of the house, or lines that connecting opposite edges of a regular tetrahedron
Other examples of skew lines can be found in non co-planar non parallel, parts of a bridge.