Eric Nicholas K's answer to Cason's Secondary 3 A Maths Singapore question.

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Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
For part i, note that "BD bisects AC at M" implies that AM = CM, or M is the midpoint of AC.

We use this fact AND the fact that BD is perpendicular to AC to help us find the equation of BD.

For part ii, the x-intercept can be found by setting y = 0.

For part iii, we use the fact that M is the midpoint of BD since ABCD is a parallelogram.