converting a function to maxterm boolean algebra

Question

Consider $f=(A+B+C'+D')(B'+C'+D)(A'+C+D')$ .

Is there any simple approach for converting $f$ to multiplication of Maxterms or even sum of minterms?

Answer 1

Just see what variables are missing and add corresponding expression.

For example, the term $(B'+C'+D)$ has no reference to $A$, so add $AA'$:

$$B'+C'+D=B'+C'+D+AA'=(A + B' +C'+D)(A'+B'+C'+D)$$

Similarly for the third term that's missing a reference to $B$, and you're done.