Section: Week 04: Sept. 13 | MAT 112A (Fall 2021) - Calculus I and Modeling | Davidson College

Main course page

Week 04: Sept. 13

  • Week 04: Sept. 13

    • Read 3.4

      • Prob A.  If f(x)=x, prove f '(x)=1 by definition of derivative.

      • Prob B.  If f(x)=x4, prove f '(x)=4x3 by definition of derivative (expand (x+h)4).
      3.4; 1, 15+, 17+, 38, 39, 55.
      On 15 and 17, in addition to everything instructed, after you prove the derivative formula, use it to find the equation of the tangent line to the curve at x=3.

    • Read 3.5 and 4.1.
      3.5; 6, 7, 8, 9, 10, 12.
      4.1; 3, 12, 17, 20, 32.
      On 20:  Rewrite as powers of x; don't use quotient rule.

    • Read 4.2.
      Prob A:  If f(x) = c u(x), prove f '(x) = c u'(x) by definition of derivative.
      4.1; 43, 57, 58abcd, 62, 71.  (Hints below; remember to include units in 62 and 71)
      4.2; 7, 19, 22, 29, 30, 33.   (Instructions specify use product or quotient rule, so you must!)

      Hint for 4.1 probs:  Easier not to use quotient rule, instead pull constants out front and/or use negative exponents.
      Hint on 56d: Units of BMI are just that, units of BMI. Describe the derivative as how much something changes for every what?
      Optional star (hand in separately within a week): do the pair of problems *(4.1;65 and 4.2;37 ).