# Linear Algebra Zeros

#### knutarve12

##### New member
Hello, I need to find the real/complex zeros for the following polynom:

t^9 - 1

Here I also need to use the exponential form of complex numbers

#### Jomo

##### Elite Member
I will help you with one of them and then you show your work for the others.
t=1 is a zero.
Did you notice that you have the difference of cubes? Will that help?

#### Subhotosh Khan

##### Super Moderator
Staff member
Hello, I need to find the real/complex zeros for the following polynom:

t^9 - 1

Here I also need to use the exponential form of complex numbers
Hint:

Use

cos[2*n*$$\displaystyle \pi$$] + i * sin[2*n*$$\displaystyle \pi$$] = 1

#### Jomo

##### Elite Member
Where n is an integer

#### Subhotosh Khan

##### Super Moderator
Staff member
Where n is an integer
Correct - but hints can be "incomplete" (not wrong).

#### Jomo

##### Elite Member
Correct - but hints can be "incomplete" (not wrong).
I never said it was wrong, I just added onto it.

#### pka

##### Elite Member
I need to find the real/complex zeros for the following polynom:
t^9 - 1 Here I also need to use the exponential form of complex numbers
You are asking about the nine ninth roots of $$1$$.

These are $$\exp\left(\dfrac{2k i\pi}{9}\right),~k=0,1,\cdots 8$$