Engineering Mathematics - Online Test

Q1. An analytic function of a complex variable z = x + iy is expressed as f(z) = w(x, y) + iv(x, y), where i = −1. If u(x, y) = x2 – y2, then expression for v(x, y) in terms of x, y and a general constant c would be 
Answer : Option C
Explaination / Solution:

Given f(z) = w(x, y) + iv(x, y),  is analytic and x = x2 - y2
We know that if f(z) =  µ+iv  is analytic then C-R equations will be satisfied.
∂µ/∂x = ∂v/∂xy and ∂µ/∂y = -∂v/∂x
v = 2xy + c is correct answer

Q2. Consider two solutions x(t) = x1(t) and x(t) and x(t) = x2(t) of the differential equation  The Wronskian 
Answer : Option A
Explaination / Solution:

Given Differential equation is


Q3. A series expansion for the function sinθ is
Answer : Option B
Explaination / Solution:



Q4. What is  equal to?
Answer : Option D
Explaination / Solution:

Applying L’ Hospitals rule, we have 

Q5. Eigen values of a real symmetric matrix are always
Answer : Option C
Explaination / Solution:

Eigen values of a real symmetric matrix are always real

Q6. The product of two complex numbers 1 + i and 2-5i is
Answer : Option A
Explaination / Solution:

(1 + i)(2 -5i) = 2 - 5i + 2i + 5 = 7 - 3i

Q7. If f(x) is an even function and a is a positive real number, then  equals
Answer : Option D
Explaination / Solution:



Q8. The integral  when evaluated by using Simpson’s 1/3 rule on two equal subintervals each of length 1, equals
Answer : Option C
Explaination / Solution:



Q9. Consider the differential equation  . The general solution with constant c is
Answer : Option D
Explaination / Solution:
No Explaination.


Q10. An unbiased coin is tossed five times. The outcome of each toss is either a head or a tail. The probability of getting at least one head is
Answer : Option D
Explaination / Solution:

 P(at least one head) = 1- P (no heads) = 1 - (1/25) = 31/32