Question

If the value of the polynomial m³ + 2m + a is 12 for m = 2, then find the value of a.

Answer 1

p(m) = m³ + 2m + a 

∴ p(2) = (2)³ + 2(2) + a 

∴ 12 = 8 + 4 + a … 

[∵ p(2) = 12] 

∴ 12 = 12 + a 

∴ a = 12 – 12 

∴ a = 0