A, B & C form the vertices of a triangle. ∠
CAB = 90°,
∠
ABC = 64° and AC = 8.7.
Calculate the length of AB rounded to 3 SF.

Do this problem by substituting the points one by one into  y < x^2 - 4x + 3.for example, determine whether (1,0) is in the solution set.  write:     0< (1)^2 - 4(1) + 3, or 0 < 1 - 4 + 3, which is false.  thus, (1,0) is not in the solution set.  go on and check the other two points, (-3,0) and (2,-1).