--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/using_sage/questions.rst Wed Dec 01 16:51:35 2010 +0530
@@ -0,0 +1,99 @@
+Objective
+---------
+
+1. How do you find the limit of the function ``x/sin(x)`` as ``x`` tends to
+ ``0`` from the negative side.
+
+ Answer: lim(x/sin(x), x=0, dir="below")
+
+#. Find the third differential of the function ``exp(sin(x)*cos(x^2))``
+
+ Answer: diff(exp(sin(x)*cos(x^2), x, 3)
+
+#. Solve the system of linear equations::
+
+ x-2y+3z = 7
+ 2x+3y-z = 5
+ x+2y+4z = 9
+
+ Answer::
+
+ A = Matrix([[1, -2, 3],
+ [2, 3, -1],
+ [1, 2, 4]])
+
+ b = vector([7, 5, 9])
+
+ solve_right(A, b)
+
+#. How do you get the factorized form of ``x^4 - 4x^2 + x^3 + 2x + 7``
+
+ Answer::
+
+ factor( x^4 + x^3 - 4*x^2 + 2*x + 7 )
+
+#. list all the primes between 2009 and 2900
+
+ Answer: prime_range(2009, 2901)
+
+#. Which function is used to check primality
+
+ a. isPrime
+ #. isprime
+ #. is_prime
+ #. prime
+
+ Answer: is_prime
+
+#. How do you list all the combinations of ``[1, 2, 3, 4]``
+
+
+ Answer::
+
+ c1 = Combinations([1, 2, 3, 4])
+ c1.list()
+
+#. How do you list all the permutations of ``[1, 3, 2, 3]``
+
+ Answer::
+
+ p1 = Permutations([1, 3, 2, 3])
+ p2.list()
+
+
+Programming
+-----------
+
+1. Obtain the sum of primes between 1 million and 2 million.
+
+ Answer::
+
+ prime_sum = 0
+ for i in range(1000001, 2000000, 2):
+ if is_prime(i):
+ prime_sum += i
+
+ prime_sum
+
+ OR
+ ::
+
+ sum(prime_range(1000000, 2000000))
+
+2. ``graphs.WorldMap()`` gives the world map in the form of a
+ graph. ::
+
+ G = graphs.WorldMap()
+ G.vertices()
+
+
+ Suppose, I wish to go from India to France by Road, find out the
+ least number of Visas that I'll have to obtain.
+
+ Answer::
+
+ G.distance("India", "France")
+
+
+
+