Let and be two points in the plane.

MATHEMATICS · Multi-part · A Level · Mathematics · Coordinate geometry in the (x y) plane · Coordinate geometry in the (x y) plane

Problem

Let

P\left(\dfrac{1}{2}, \dfrac{3}{4}\right)

and

Q\left(\dfrac{5}{2}, -\dfrac{7}{4}\right)

be two points in the plane. (a) Find the slope of the line segment

PQ

. (b) Obtain the equation of the straight line passing through

P

and

Q

in slope–intercept form. (c) Using your equation from part (b), determine the value of

y

when

x = 4