Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
secondary 4 | A Maths
One Answer Below
Anyone can contribute an answer, even non-tutors.
Good morning everyone!!!! Would really appreciate if someone can help me with this particular question :) Thank you
See 1 Answer
In this case, we only know that the shortest point from A to line BC is when a line passes through A to be perpendicular to line BC at point D.
At this point, however, we do not have the coordinates of D, which we would need to find to obtain the length of AD.
Hence, to find the required coordinates, we will have to form an equation AD based on our knowledge of linear equation forming. The two lines AD and BC must meet at D, and this is when we use the two equations to solve for the coordinates of D.
Unlike the E Maths trigo case which you are immediately given lengths to work out this shortest length, we do not have the other lengths (or even area) to work out this shortest length. We are only given one coordinate to work with, along with the equation of a line. Therefore, this approach is the way to go for such questions.
Hope this helps!