MTH108: HOMEWORK 1 – WARM-UP PROBLEMS
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MTH108: HOMEWORK 1 – WARM-UP PROBLEMS
Section A – Warm-up questions
A1. If y x u2 /v , then what is the effect of simultaneously decreasing u by 20% and v by 60%?
A2. Sektch the graphs of the following functions f : R → R:
x
(i) f (x) = 2 _ e-Ⅹ ; (ii) f (x) = ; (iii) (iii) f (x) = e-Ⅹ cos(x) .
A3. Identify the set of real numbers x that satisfy lx2 _ 4x l s 2x .
A4. Use the Intermediate Value Theorem to prove that x3 + x _ 1 has a positive root .
A5. Describe how the behaviour of the sequence (xn ), where xn = rn , depends on the real parameter r . A6. How does the number of real roots of x3 _ 12x2 + 36x + r depend on the real parameter r?
A7. For which real values of r is the matrix ╱ 1(r) 2(r2)、 invertible?
A8. For which real values of r does the matrix 、 have a real eigenvalue?
Section C – Investigations
C1. Consider the function F : Z+ → Z+ defined on the positive integers by
F (x) = ,
Investigate what happens if we take a positive integer starting value x and apply the function F over and over again .
C2. Consider a set A with finitely many elements and a function F : A → A . Investigate what happens if we take an element a e A and then apply the function F over and over again . Try to make a conjecture that describes the behaviour of sequences of the form
a, F (a), F (F (a)), F (F (F (a))) , . . .
and then prove the conjecture .
2022-08-08