Find all integer values of a such that
the quadratic expression
(x + a)(x + 1991) + 1 can be factored
as a product (x + b)(x + c) where b and
c are integers.
If x, y, z are three real numbers such
that x + y + z = 4 and x^2 + y^2 + z^2 = 6,
then
(1) (2/3) ≤ x, y, z ≤ 2
(2) 0 ≤ x, y, z ≤ 2
(3) 1 ≤ x, y, z ≤ 3
(4) 2 ≤ x, y, z ≤ 3
Let p = (x_1 − x_2 )^2 + (x_1 − x_3 )^2 + .... +
(x_1 − x_6 )^2 + (x_2 − x_3 )^2 + (x_2 − x_4 )^2 +
.... + (x_2 − x_6 )^2 + .... + (x_5 − x_6 )^2 =
Σ_(1≤i<j≤6) ^6 (x_i − x_j )^2 .
Then the maximum value of p if each
x_i (i = 1, 2, ....., 6) has the value 0 and
1 is
Suppose p is a polynomial with complex
coefficients and an even degree. If all
the roots of p are complex non-real
numbers with modulus 1, prove that
p(1) ∈ R iff p(−1) ∈ R.
Let n be an even positive integer such
that (n/2) is odd and let α_0 , α_1 , ...., α_(n−1) be
the complex roots of unity of order n.
Prove that Π_(k=0) ^(n−1) (a + bα_k ^2 ) = (a^(n/2) + b^(n/2) )^2
for any complex numbers a and b.
The locus of the centre of a circle which
touches the given circles ∣z − z_1 ∣ =
∣3 + 4i∣ and ∣z − z_2 ∣ = ∣1 + i(√3)∣ is a
hyperbola, then the length of its
transverse axis is
If [ ] represents the greatest integer
function and f(x) = x − [x] then
number of real roots of the equation
f(x) + f((1/x)) = 1 are infinite.
True/False
For any integer k, let α_k = cos (((kπ)/7)) +
i sin (((kπ)/7)), where i = (√(−1)). The value of
the expression ((Σ_(k=1) ^(12) ∣α_(k+1) − α_k ∣)/(Σ_(k=1) ^3 ∣α_(4k−1) − α_(4k−2) ∣)) is
Let f(x) = ax^2 + bx + c, where a, b, c
are real numbers. If the numbers 2a,
a + b, and c are all integers, then the
number of integral values between 1
and 5 that f(x) can take is
For each positive integer n, consider
the highest common factor h_n of the two
numbers n! + 1 and (n + 1)!. For n < 100,
find the largest value of h_n .
(A) If ∣w∣ = 2, then the set of points
z = w − (1/w) is contained in or equal to
(B) If ∣w∣ = 1, then the set of points
z = w + (1/w) is contained in or equal to
Options for both A and B:
(p) An ellipse with eccentricity (4/5)
(q) The set of points z satisfying Im z
= 0
(r) The set of points z satisfying ∣Im z∣
≤ 1
(s) The set of points z satisfying ∣Re z∣
≤ 2
(t) The set of points z satisfying ∣z∣ ≤ 3
Let f(x) = ∣x − 1∣ + ∣x − 2∣ + ∣x − 3∣,
then find the value of k for which f(x)
= k has
1. no solution
2. only one solution
3. two solutions of same sign
4. two solutions of opposite sign