The gradient of CP is |
| = |
| = | –1 |
The gradient of the tangent is perpendicular to this, i.e. | 1 |
![]() | y = | x + const | ![]() | y – x = c |
To find c, the tangent goes through P( –11, 12): 1( 12) –1( –11 ) = cc = 23
![]() | y – x – 23 = 0 | or any multiple of this equation. |
© MEI Produced by Dr Ron Knott, revised 5 August 2004![]() | Test reference: GeomCircleTanNorm.html?ref=39633 |