We have an arithmetic progression:
An arithmetic progression is a sequence of numbers such that the diference between the consecutive terms is constant.
Explicit formula:
an=a₁+(n-1)*d
a₁ is the first term
d is de common diference
n is the numbers of terms
In this case:
a₁=-9
d=an-an-1=a₂-a₁=-16-(-9)=-16+9=-7
an=-9+(n-1)*(-7)
an=-9-7n+7
an=-7n+-2
a₁=-7*1-2=-9
a₂=-7*2-2=-14-2=-16
a₃=-7*3-2=-21-2=-23
a₄=-7*4-2=-28-2=-30
a₅=-7*5-2=-35-2=-37
a₆=-7*6-2=-42-2=-44
1130.97 is the surface area of the cylinder
Note what i actually represents.
i is the very basis of a whole new level of counting. When finding discriminants, we often say that a quadratic has no
real roots if the discriminant is 0. Needless to say, there are roots, they are just imaginary.
, in real terms, is non-existent. That is, there are no numbers in the real number system that when multiplied by itself produces a result of -1. This is what i unit represents.
Let's tackle this problem in smaller steps.
Let's first expand our brackets.
(i - 7i)² = (-6i)² = 36i²
Now, let's distribute the xi.
xi(i - 7i)² = xi(36i²) = 36xi³ =
= -36xi