Answer
(a) $-1,0,4$ each with multiplicity of 1.
(b) see graph.
Work Step by Step
(a) Find all real zeros of P, and state their multiplicities.
$P(x)=x(x^2-3x-4)=x(x-4)(x+1)$, zeros $-1,0,4$ each with multiplicity of 1.
(b) Sketch the graph of P.
see graph.
