Let P(3, 4) be a point on the circle x2 + y2 = 25. (Note: Organize your work by part.)
What is the slope of the line joining P and O (0, 0)?
Find an equation of the tangent line to the circle at P. (NOTE: Remember that a line tangent to a circle is perpendicular to the radius at the point of tangency.)
Let Q(x, y) be another point on the circle in the first quadrant. Find the slope mx of the line joining P and Q in terms of x.
Calculate lim→3 mx How does this number relate to your answer in part b?

Find the limit, if it exists, analytically using special trig limits of lim x→0 1-cos27x8x2(1-sin27x)