Midlands State University Department of Mathematics HMT101 Calculus I Lecturer: W D Govere Dept of Applied Education AEM102 Calculus Module Outline a) b) c) d) e) f) g) h) i) Number Systems: natural, integral, rational and irrational numbers Mathematical induction The real number system: decimal and geometric representation Inequalities and their solutions Sequences Functions: exponential, logarithmic, trigonometric and hyperbolic and their inverses Limits and continuity Differentiation: derivatives of a single variable Integration: definite and indefinite integrals, techniques of integration: method of substitution, integration by parts and reduction formulae, fundamental theorem of calculus Recommended reading L Hostetler- Calculus E L Swokowski- Calculus Spiegel- Advanced Calculus L M Mudehwe- Calculus 1 (ZOU Module) Any other text on Calculus 1 Tutorial Worksheet 1 Number Systems / Induction / Inequalities 1. Prove that (i)3, (ii) 5, cannot be rational. 2. Show that 2+3 cannot be rational. 3. Show that 7-3 is irrational. 4. Assuming that 5 is irrational show that (2+5) is irrational. m r 5. Assuming that 2 is irrational, show that if and are rational numbers with n s r m r 0 then 2 is irrational. s n s 6. Prove that between any two rational numbers there is a rational number. p 7. Express 0.mnmnmn... where m and n are distinct integers, in the form where p q and q are integers. 8. Does the decimal 0.123456789101112131415161718… whose digits are natural numbers strung end-to-end represent a rational or irrational number. Give a reason for your answer. 9 Write down the following terminating decimals as recurring decimals: 0.23, 0.325, 0.108 10 Express the following recurring decimals as terminating decimals: . . . 0.74 9, 8.003 9, 316.319 Prove the following by PMI: n n(n 1) n(n 1)( 2n 1) 11. (a) r (b) r 2 6 2 r 1 r 1 12. (1 x) n 1 nx , n 2,3,... x 1, x 0 n n(n 1) (c) r 2 r 1 n 2 3 13. n 2 n n N . Hint: Note that 2k = k + k. 14. 4 n 3n 2 1 n 2 15. n! n 2 n 4 16 a ar ar 2 ... ar n 1 a(r n 1) , r 1 r 1 d 2n 17 Deduce a formula for (sin x) in terms of sin x and prove your formula for all dx 2 n n using PMI. n n(n 1)( n 2) 18 Using the results in 11(a) & (b) show that r (r 1) and prove 3 r 1 this result by PMI. 1 1 1 19. Deduce a formula for the sum and prove it by PMI. ... 1 2 2 3 n(n 1) Solve the following inequalities: 20. x 2 3x 2 10 2 x 21. | x 1 | 2 x 1 2 22. | 3x 5 | 9 23. | x 1 | 3 | x 2 | | x | 2 4 24. x2 25 Solve the inequality 5x 9 2 x 3 and indicate your solution on the real number x 1 line. 26 Show that x, y, z R, x 2 y 2 z 2 xy yz xz 3 Tutorial Worksheet 2 Sequences 1.Write down the 1st five of each of the following sequences 1 1 n n 1 (1) n 1 cos n n (a) (e) 1 (f) (1 n) n (b) n (c) (d) 2 n (n 1) n! n 1 (g) S1 1 , S n1 3S n 1 2. Write down the 6th and 7th terms of each of the following sequences and give a formula for the nth term. 1 3 5 7 9 , , , , , ... 5 8 11 14 17 (b) 1,0,1,0,1,… 1 1 1 (c) , 0, , 0, , ... 2 3 4 (d) 5,5,5,5,5,… 2 3 4 (e) , 0, , 0, , ... 3 4 5 3. Consider the following sequences {S n } , where (a) 1 2n 3 2n 2n 2 1 (b) S n (c) S n (d) S n 2 4n 3n 2 n 1 n For each of the above sequences, (i) find the number l to which the sequence converges (ii) Generally, if > 0, provide an expression for N in terms of such that | S n l | whenever n N (iii) find the range of values for the index n such that | S n l | 0.01 (a) S n 3 4. State whether each of the following sequences {S n } tends to a limit, and if so, what the limit is. Use the definition in terms of and N to prove your answers correct. (a) S n n (f) S n 1 (b) S n 2 n 1 2 2n 1 1 (d) S n (e) S n 2n 2 n (c) S n (1) n n n 1 5. For {S n } given by the following formulae, establish either the convergence or divergence of {S n } . n(1) n n2 2n 2 3 nn 1 (1) n (a) (e) (b) (c) 2 (d) n 1 n n 1 n 1 n 1 (n 1) (f) ln n ln( n 1) 6. Find the limit of each of the following sequences en cos 2 n 5n cos n (a) 2 n (b) 4 (c) e n ln n (d) n (e) e n 3 n 2 3n 5n 4 (f) 2 n 7 4 7 Draw a graph for each of the following sequences and describe whether the sequence is monotone, convergent or divergent, etc. 1 1 1 1 1 (a) , , , , , ... 3 5 7 9 11 1 (b) {S n } defined recursively by S1 2 , S n 1 2 Sn n (1) n (d) S n 1 n 1 n 8 Evaluate (c) S n n 3 (i) lim n n 5 2 n 5 n 1 (iv) lim n n 2 2n 2 (ii) lim 2 n 2n 5 3n 2 2n 4 (v) lim n 2 n 3 3n 2 5 n8 (iii) lim n n 2 2n n 2 n 1 n 1 1 9. (a) Show that lim 1 n e n (b) Investigate the behaviour (by sketching a graph) of the following sequence n n 1 when n is odd sn 1 1 when n is even n 10. Find the limits of the following sequences 2 n n (1) n n 1 1 1 1 (a) 2 (b) 1 (c) (d) (e) 1 2 n n n n n n2 11. (a) Suppose {s n } is a sequence converging to 0, and {t n } another sequence such that 0 t n s n n . Show that {t n } converges to 0. 1 (b) Investigate the behaviour of the sequence {n 2 n } , i.e find out whether it is monotone increasing / decreasing, bounded below / above, convergent / divergent. [A graph may be useful]. 12. Show that lim 2 n 3n n 1 n 3 5 Tutorial Worksheet 3 Functions, Limits & Continuity Q1 Sketch the graphs of the functions (i) tan x (ii) cot x (iii) sec x (iv) csc x . Q2 Sketch the graphs of the functions (i) cos 1 x (ii) tan 1 x (iii) sec 1 x (iv) csc 1 x . Q3 Sketch the graphs of the functions (i) tanh x (ii) coth x (iii) sec hx (iv) cos echx . Q4 Sketch the graphs of the functions (i) tanh 1 x (ii) coth 1 x (iii) sec h 1 x (iv) cos ech 1 x . Q5 Verify each of the following identities 1 cosh 2 x (a) cosh 2 x cosh 2 x sinh 2 x (b) cosh 2 x (c) tanh 2 x sec h 2 x 1 2 Q6 Show that (a) cosh 1 x ln x x 2 1 , x [1, ) 1 1 x (b) tanh 1 x ln , 1 x 1 2 1 x 1 1 x2 , 0 x 1 (c) sec h 1 x ln x Q7 Find the domain of each of the following functions of real numbers. (3x 5)( x 4) (a) f ( x) (b) f ( x) 4 x ln( x 3) (c) f ( x) sin 5 x x 3 16 x Q8 Find the range of each of the following functions 1 (a) f ( x) x 2 9 (b) f ( x) x | x | (c) f ( x) (d) f ( x) ln( x 3) ( x 3) 2 Q9 Use the definition of a limit to prove that (a) lim (2 x 3) 5 (b) lim (5 x 7) 2 (c) lim (3 x 7) 10 x 1 x 1 x 1 (d) lim (3x 7 x 1) 49 2 x3 (e) lim ( x 6) 5 (f) lim (2 x 2 5x 6) 4 3 x1 x2 2 , x 1 Q10 Let f ( x) 2 1 x , x 1 (a) Draw the graph of f (b) Determine lim f ( x) and lim f ( x) x 1 x 1 (c) Does lim f ( x ) exist? Give a reason for your answer. x1 Q11 Suppose that lim f ( x) l1 and lim g ( x) l 2 , then prove that x x0 (a) lim ( f ( x) g ( x)) l1 l 2 x x0 x x0 (b) lim cf ( x) cl1 x x0 Q12 Determine the following limits 2 x 2 x x3 1 (a) lim (b) lim x 0 x 1 x 2 x 2 x x 1 3x 1 (d) lim (e) lim 2 x | 2 x | x 1 x 24 x 5 3 5x 2 x 1 (g) lim 2 (h) lim x 8 x 3 x 0 x 1 x4 1 (c) lim x 1 x 1 |x| (f) lim x | x | 1 (i) lim x x x 1 2 6 (j) lim x (m) lim x 1 x 3x 4 8 x 3 16 x 2 x 3 3 x 2 4 (k) lim 1 cos 2 x (n) lim x x 2 1 cos x (p) lim x 0 x2 x x4 x (l) lim x x (o) lim x 0 2 x 2 3x 2 x sin 3 x x 2 (q) lim (1 cot x) x Q13 Find lim f ( x) if x tan x (r) lim (cos x) x 2 x 0 2 2x 2 2x 2 5 . f ( x ) x2 1 x2 Q14 Use the squeeze theorem to determine lim x sin x . x Q15 Evaluate each of the following limits x8 (a) lim x x 2 (e) lim (1 3x) x 0 2x 2 x 2x 1 (b) lim x 2 x 3 (f) lim (1 2 x) x 3 x x 0 x 1 (c) lim x x 2 3x2 x 2 (d) lim x x 1 3x2 2x 2 ln( 1 x) (g) lim (h) lim 2 x 2 x 5 x 0 x 3 x 2 5 4 x 2 , x 1 Q16 Let f ( x) 2 3 x , x 1 (a)Draw the graph of f (b)Determine lim f ( x) and lim f ( x) x 1 x 1 (c) What value, if any, must be assigned to f (1) to make f continuous at x =1? Give a reason for your answer. x 2 2 x 15 , x3 Q17 Let g ( x) x3 k , x3 What value, if any, must k be so that g is continuous at x = 3? Give a reason for your answer. Q18 The function f : R R is defined by 1 x sin , x 0 f ( x) x 0 , x 0 Prove that f is continuous at x = 0. 7 Tutorial Worksheet 4 Differentiation, Integration Q1 Show that 2 1 x sin , x 0 (a) f ( x) is differentiable at x = 0. x 0 , x0 1 x sin , x 0 (b) f ( x) is not differentiable at x = 0. x 0 , x0 Q2 (a) Use the definitions of cosh x and sinh x to show that d d cosh x sinh x and sinh x cosh x (i) (ii) dx dx (b) Use the results in (a) to show that d d tanh x sec h 2 x coth x cos ech 2 x (i) (ii) dx dx d d sec hx sec hx tanh x (iv) cos echx cos echx coth x (iii) dx dx Q3 Compute the derivative of each of the following functions 1 ( x 1) 2 (a) x 3 sin x (b) (c) (d) sin 3 (6 x) 2 5 2 (3x 2 x 1) 3x (e) x 6 ln( 3x 2 5 x 7) (f) ln( x 1 x 2 ) Q4 Compute the derivative of each of the following functions (a) sin 1 x (b) sinh 1 x (c) tan 1 x (d) tanh 1 x (e) cos ech 1 x (f) x sin x (g) x cos x dy 1 x Q5 If y cos 1 . , find dx 1 x d 1 Q6 Let cosh 1 x ln( x x 2 1) . Show that . cosh 1 x 2 dx x 1 Q7 Evaluate the following integrals 3 2x 3 6 x 3 13x 2 7 x 10 dx (ii) (i) 2 (iii) x 2 e ( x 6) dx dx 2 x 4x 5 3x 2 x 5 1 1 x dx dx (iv) ( x 2 2 x 2) cos( x 3 3x 2 6 x 7)dx (v) (vi) 2 2 x (ln x) x 1 (vii) 1 1 x (ln x) dx (viii) cos x sin x cos x sin x dx (ix) tan 1 x 1 x 2 dx (x) 2x 7 4x dx 7x 5 2 3x 3 11x 2 3x 2 dx (xi) x( x 1) 3 Q8 Evaluate (i) ln xdx (ii) tan 1 xdx (iii) sin 1 xdx Q9 Find the reduction formula for S n sin n xdx 8 Q10 If I n 2 x n sin xdx prove that I n n 0 2 evaluate I 4 . n 1 n(n 1) I n 2 . Hence or otherwise Q11 Let I n e x sin n xdx . Show that (1 n 2 ) I n n(n 1) I n 2 n 2 . Hence or 0 otherwise evaluate I 4 . 9