The table is for the relation \(y = px^{2} - 5x + q\).

x	-3	-2	-1	0	1	2	3	4	5
y	21	6		-12				0	13

(a)(i) Use the table to find the values of p and q.

(ii) Copy and complete the table.

(b) Using scales of 2cm to 1 unit on the x- axis and 2 cm to 5 units on the y- axis, draw the graph of the relation for \(-3 \leq x \leq 5\).

(c) Use the graph to find : 

(i) y when x = 1.8  ; (ii) x when y = -8.