MATH0045
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MATH0045
Answer all questions .
Section A
1. (1) Let f (北) = cos 北. Using the limit definition of the derivative only, show that f\ (0) = 0.
(2) Compute the following limits (a)
北2 + 5 − e_
lim
(b)
北2 + 5 − e_
z →o 北2 + 2
.
(15 marks)
2. Compute the following integrals (a)
t11 sin(t6 )dt
(b)
2北3 − 7北2 + 13北 − 9
d北
(北2 + 1)(北 − 2)2
.
(15 marks)
3. (a) Find all the critical points of the function
g(北, y) = 3北y2 + 北3 − 3y2 − 3北2 + 2
(b) For each critical point of g, determine whether it is a local minimum, a local maximum, or a saddle point.
.
(15 marks)
Section B
4. (a) (1) Let
f (北, y) = 7y2 + sin(3北) − 12 + y4
Use the implicit function theorem to show that the equation f (北, y) = 0
[with f (北, y) as above] can be rewritten as y = g(北).
(2) Find an expression for g\ (北) in terms of 北 and g(北).
(b) Find the first three nonzero terms of the Taylor expansion of
1
1 + 北9
about 北 = 0.
.
(20 marks)
5. Consider the system A北 = b where
A = 1(1) .(、) 北 = .(、) and b = .(、)
(a) Construct the matrix (A b) and find its row reduced echelon form. (b) Find all solutions of the system A北 = b.
(c) What is the rank of A?
(d) Find the determinant of A.
(e) Is the matrix A invertible? If so find the inverse A_1 of A.
.
(20 marks)
6. (1) Determine whether or not the following series converge or diverge. Jus- tify your answer.
(a)
sin(2n)
n=1
(b)
o 7n
( −3)n+1n
n=1
(2) Determine for which values of 北, the series converges or diverges
o (北 − 4)n
(n + 1)3n+1
n=0
.
(15 marks)
2022-08-11