= mx + c . Again assuming F along x - axis and K along y - axis , we can take equation in the form K = m F + c ... ( ) Equation ( ) is satisfied by ( , ) and ( , ). Therefore = m + c ...
( ) and = m + c ... ( ) Solving ( ) and ( ), we get m = and c = Putting the values of m and c in ( ), we get K F ... ( ) which is the required relation. When K = , ( ) gives F = – .
. A Note We know, that the equation y = mx + c, contains two constants, namely, m and c. For finding these two constants, we need two conditions satisfied by the equation of line. In all the examples above, we are given two conditions to determine the equation of the line.
EXERCISE . In Exercises to , find the equation of the line which satisfy the given conditions: . Write the equations for the x -and y -axes. .
Passing through the point (– , ) with slope . Passing through ( , ) with slope m . .