1 123 New member Joined Nov 6, 2010 Messages 46 Nov 9, 2010 #1 With which p meaning equation \(\displaystyle 3a^2+pa+24=0\) what rule I can use here or something? [/i]

With which p meaning equation \(\displaystyle 3a^2+pa+24=0\) what rule I can use here or something? [/i]

B BigGlenntheHeavy Senior Member Joined Mar 8, 2009 Messages 1,577 Nov 9, 2010 #2 \(\displaystyle a \ = \ 3 \ is \ a \ solution \ to \ the \ equation \ f(a) \ = \ 3a^2+pa+24.\) \(\displaystyle Hence, \ f(3) \ = \ 0 \ = \ 27+3p+24 \ (why?), \ \implies \ p \ = \ -17.\) \(\displaystyle I'll \ let \ you \ do \ the \ check.\)

\(\displaystyle a \ = \ 3 \ is \ a \ solution \ to \ the \ equation \ f(a) \ = \ 3a^2+pa+24.\) \(\displaystyle Hence, \ f(3) \ = \ 0 \ = \ 27+3p+24 \ (why?), \ \implies \ p \ = \ -17.\) \(\displaystyle I'll \ let \ you \ do \ the \ check.\)