How do you factor the expression 64x^2 + 81?
3 Answers
Explanation:
If
As a result
We can do something with Complex coefficients...
First notice that
The difference of squares identity can be written:
a^2-b^2 = (a-b)(a+b)
The imaginary unit
Hence we find:
64x^2+81
=(8x)^2+9^2
=(8x)^2-(9i)^2
=(8x-9i)(8x+9i)
If we want to, we can write a "sum of squares" identity:
a^2+b^2 = (a-bi)(a+bi)
(there are no factors with only Real components)
Explanation:
Remember that
If there were any factors with only Real components the equation
however we can tell from the fact that the discriminant