

PROVE: 4. If f : R → R is a strictly increasing function, f(0) = 0,...
A function f:R HR is said to be strictly increasing if f(x1) < f(12) whenever I] < 12. Prove: If a differentiable function f is strictly increasing, then f'(x) > 0. Then give counterexamples to show that the following statements are false, in general. (i) If a differentiable function f is strictly increasing, then f'(2) >0 for all 1. (ii) If f'(x) > 0 for all x, then f is strictly increasing -
Prove that if ? is integrable on [?, ?] and ?(?) ≥ 0 for all ?
in [?, ?], then
[ f(x)dx > 0 7. Prove that if f is integrable on [a, b] and f(x) > 0 for all x in [a, b], then sof(x)dx > 0.
R such that f is integrable on every [a,b] (6) Suppose f is a function and a where b> a. Then we define the improper integral eb f(x)dx=lim | b-oo Ja f(x)da, if that limit exists. Assume that f(x) is continuous and monotonically decreasing on [0,00). Prove that Joof exists if and only if Σ f(n) converges. This result is known as the integral test for series convergence.
Prove or Disprove:
Let p E P(F) and suppose that deg p > 1 and p is irreducible. Then p(a)メ0 for all a E F.
Prove that is an integer for all n > 0.
4. (a) Suppose that limz-c f(x) = L > 0. Prove that there exists a 8 >0 such that if 0 < 12 – c < 8, then f(x) > 0. (b) Use Part (a) and the Heine-Borel Theorem to prove that if is continuous on (a, b) and f(x) > 0 for all x € (a, b), then there exists an e > 0 such that f(x) > € for all x € [a, b].
For all n E N prove that 0 <e- > < 2 k!“ (n + 1)! k=0 Hint: Think about Taylor approximations of the function e".
(a) (4 marks) Consider the function S(x) = x-cos(x). 1) Prove that S has at least one zero in the interval [0, ) f(0)f(x) <0. (O)f(x) > 0 and is continuous f(0)f(x) < 0 and is continuous. ii) Prove that S has at most one zero in the interval [0, x) f' <0 on (0,#] so that is strictly increasing on (0,r)- 1'>0 on (0,#] so that f is strictly increasing on (0, #) 1'>on (0,r) so that is strictly...
Q3. Find the quantile function F-1 for F(r)-1-1-α, x > 1.
For what values of x is the function f(x) = x3 + 15 x2 + 63 x increasing? f(x) is increasing when z 〈 and when x>