a,

b,

Thay x=-4 vào (P), ta được:

\(y = 2 \cdot \left(\left(\right. - 4 \left.\right)\right)^{2} = 2 \cdot 16 = 32\)

=>\(M \left(\right. - 4 ; 32 \left.\right) \in \left(\right. P \left.\right)\)

Thay \(x = - \frac{1}{2}\) vào (P), ta được:

\(y = 2 \cdot \left(\left(\right. - \frac{1}{2} \left.\right)\right)^{2} = 2 \cdot \frac{1}{4} = \frac{1}{2}\)

=>\(N \left(\right. - \frac{1}{2} ; \frac{1}{2} \left.\right) \in \left(\right. P \left.\right)\)

Thay \(x = \frac{3}{4}\) vào (P), ta được:

\(y = 2 \cdot \left(\left(\right. \frac{3}{4} \left.\right)\right)^{2} = 2 \cdot \frac{9}{16} = \frac{9}{8}\)

=>\(Q \left(\right. \frac{3}{4} ; \frac{9}{16} \left.\right) \notin \left(\right. P \left.\right)\)