Name_____KEY_____________ Chapter 2 Review Limits and continuity Per.______ For the following functions a. Find the intervals of continuity of each function b. Label each discontinuity as removable or non-removable c. IF the discontinuity is removable then write the extended function that is continuous at that domain value. 4 x a. (, 0) (0, ) b. f has an infinite discontinuity at x = 0. c. x = 0 is not a removable discontinuity 1) f ( x) 3 2) g (t ) t 3 2t 2 t t 2 1 a. (, 1) (1,1) (1, ) b. f has an infinite discontinuity at x = -1 and a removable discontinuity at x = 1 t t 1 c. Extended function for g(t): f (t ) t 1 Rates of change: 3 do the following. n2 Name the domain of p(n): Compute the average rate of change of p(n) on the interval [3, 4]. Compute the instantaneous rate of change function of p(n) for n = 1. Write an equation for the tangent line to the curve p(n) when n = 1. Write an equation for the normal line to the curve p(n) when n = 1. 3. Given p (n) a. b. c. d. e. a. Domain: , 2 2, b. Average rate of change: p (4) p (3) 3 43 2 c. Instantaneous rate of change at n = 1: lim h 0 d. y 3 3 x 1 y3 1 x 1 3 p(1 h) p(1) 3 h A 10 ft3 wooden box with a square base of t feet by t feet is going to made of three different woods. The cost for the wood on the top is $1.15 per square foot. The sides are made of wood that is $0.50 per square foot. And the bottom material costs $0.85 per square foot. a. Write a volume equation for the box. b. Write a cost equation that is a function of only t. That is C(t). c. What is a reasonable domain of the cost function? d. Draw a sketch of C(t) on the domain from part c. e. What are the dimensions of the box that costs the least to produce? (t and height) C (tm h) C (tm ) 0 where tm is the t value from part e. f. Explain why: lim h 0 h 10 a) V (t ) t 2 h where h 2 t 10 C (t ) (1.15)t 2 4(0.50) (0.85)t 2 t b) 20 2t 2 t c) Reasonable domain: 0, 4. d) t 1.71 ft, h 3.42 ft, cost $17.54 5) Use the graph of f(x) on the right to evaluate the following limits. a. lim f ( x) x b. lim f ( x) 9 x 6 c. lim f ( x) DNE x 0 d. lim f ( x) 2 x 0 e. lim f ( x) 4 x f. lim h 0 f (1 h) f (1) 3 h g. lim h 0 f (6 h) f (6) 0 h lim 6) What does the limit 3 4 h 2 3 4 2 h 0 h tell you about the graph of the function f ( x) 3x 2 f ( x) 3x 2 The limit tells you that the slope of the curve at x = 4. 7) Find a right and a left end behavior model for the functions below. f ( x) x e x g ( x) ln x sin x a. b. y ex y ln x R.E.B.M: R.E.B.M: yx L.E.B.M. L.E.B.M. y ln x 8) An object is dropped from the top of a 200 meter tower. Its height above ground after t seconds is given by the equation h(t ) 200 4.9t 2 a. What is the average speed of the object over the first two seconds of its fall? 9.8 m/ b. When does the object hit the ground? 6.38877 seconds c. What is the object’s instantaneous speed three seconds after it begins to fall? 29.4 m/sec 9) Consider the function f ( x) 3 . x 5x 6 2 a. Is f(x) a continuous function? Explain your answer. Yes. f(x) is a rational function. The function is continuous on its domain which means that it is a continuous function. The only points of discontinuity f(x) has are x = -2 and x = -3. Both lie outside the domain of the function. b. Is f(x) continuous on the interval from [-10,10]? No. f(x) is discontinuous at x = -2 and x = -3 both of which are in the interval [-10,10]