problem: COORDINATES AND SURDS?
i'm studying maths as level on my own from text books and i'm getting stuck fairly often :)
please help me !!!
i'm stuck on part (d) of this question.
(a) find the equation of the line L through the point A(2,3) with gradient -1/2
answer = 2y = x +2
(b) show that the point P with coordinates (2 + 2t, 3 - t) will always lie on on L whatever the value of t.
which i can do. ( although i would be unsure how to word the answer in an exam).
(c) find the values of t such that the length AP is 5 units.
answer = √5 and -√5
(d) find the value of t such that OP is perpendicular ( where O is the origin ). Hence find the length of the perpendicular from O to L.
answer = the value of t is -1/5 but i have no idea how to calculate the length of O to L (OP).
can anyone walk me through it?