Question

How do you factor and simplify `1000-cos^3u`?

Answer 1

see below

Explanation:

Use the Difference of Two cubes Formula. That is,
`color(red)(x^3-y^3=(x-y)(x^2+xy+y^2)`

Hence,
`1000-cos^3u=color(blue)(10^3-(cosu)^3`

`=color(blue)((10-cosu)(10^2+10cosu+(cosu)^2)`

`=color(blue)((10-cosu)(100+10cosu+cos^2u)`