We know that the diagonals of a parallelogram bisect each other.
This means that the point O bisects diagonal AC into two equivalent segments.
Thus, we know that CO and OA are congruent. [1 Mark]
Given OC = 4x2+5 and OA = 41
Since, CO = OA ,
⇒ 4x2 + 5 = 41
⇒ x2 = 9
∴ x = 3 [1 Mark]