Section A
Q1.
(a) Let R be an integral domain. Then prove that ch R (characteristic of R) is 0 or a prime.
(b) Show that the function f(x) = sin(1)/(x)) is continuous and bounded in (0, 2π), but it is not uniformly continuous in (0, 2π).
(c)
Test the Riemann integrability of the function f defined by
f(x) = \begincases 0 & \textwhen x \text is rational \\ 1 & \textwhen x \text is irrational \endcases
on the interval [0, 1].
(d) Using Cauchy's Integral formula, evaluate the integral ∮ (dz)/((z2 + 4)2) where c: |z - i| = 2.
(e) A firm manufactures two products A and B on which the profits earned per unit are ₹ 3 and ₹ 4 respectively. Each product is processed on two machines M1 and M2. Product A requires one minute of processing time on M1 and two minutes on M2, while B requires one minute on M1 and one minute on M2. Machine M1 is available for not more than 7 hours 30 minutes, while machine M2 is available for 10 hours during any working day. Find the number of units of products A and B to be manufactured to get maximum profit, using graphical method.