 |
| ||
| |||
|
| Math Central | Quandaries & Queries |
|
Question from Jake, a student: Find an equation of the line that is tangent to the circle x2 + y2 = 3 at the point (1,√2) |
Jake,
The line you are looking for passes through the point (1,√2) so you know a point on the line and hence you can write its equation if you know its slope.
If a line is tangent to a circle at a point P then the radius from the centre of the circle to P is perpendicular to the tangent line.
The circle has its centre at (0, 0).
What is the slope of the radius from (0,0) to (1,√2)?
What is the slope of a line which is perpendicular to this radius?
Write the equation of the line with this slope and passing through (1,√2).
Penny
| ||
| ||
| ||
 |
 |
|
Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.