1. Show that, if the equations x^2 + 2px + q = 0 and x^2+2Px+Q=0 have a common root, then (q-Q)^2+4(P-p)(Pq-pQ)=0.
2. Find the conditions that the equations x^2+2x+a=0 and x^2+bx+3 should have a common root.
I have no clue how to do these problems.
Could someone please help???