Answer:

Step-by-step explanation:
It is a linear homogeneous differential equation with constant coefficients:
y" + 4y = 0
Its characteristic equation:
r^2+4=0
r1=2i
r2=-2i
We use these roots in order to find the general solution:

Answer:
44 swimmers
Step-by-step explanation:
Answer:
.
Step-by-step explanation:
Two vectors
and
are parallel to one another if and only if the ratio between their corresponding components are equal:
.
Equivalently:
.
For the two vectors in this equation to be parallel to one another:
.
Solve for
:
.
would be the only valid value of
; no other value would satisfy the
equation.
Answer:
a graphical representation of the distribution of income or of wealth.