What is the equation for the tangent line of a circle with the point on the circle (-1, 2). center of circle (2, -1). i just cant remember the formula. thanks.(worried)
What is the equation for the tangent line of a circle with the point on the circle (-1, 2). center of circle (2, -1). i just cant remember the formula. thanks.(worried)
slope of the radius connecting the center of the circle to the point on the circle ...
$\displaystyle m_r = \frac{2-(-1)}{-1-2} = -1$
slope of the tangent line is the opposite reciprocal of $\displaystyle m_r = -1$ ...
$\displaystyle m_T = 1$
tangent line equation ...
$\displaystyle y - 2 = 1[x - (-1)]$