4. In your own words, explain the three-part definition of continuity and describe the three types of discontinuities discussed in class. 5. Find constants a, b, and c such that the function f (x) = ax3 + bx2 + c will have a local extremum at (2, 9) and a point of inflection at (1, 5). 6. Using first principles (the limit definition of the derivative), determine the equation of the tangent to f (x) = x2 - 8x + 4 atx = -3