General Instructions: (i) All questions are compulsory. (ii) This question paper contains 29 questions. (iii) Questions 1- 4 in Section A are very short-answer type questions carrying 1 mark each. (iv) Questions 5-12 in Section B are short-answer type questions carrying 2 marks each. (v) Questions 13-23 in Section C are long-answer I type questions carrying 4 marks each. (vi) Questions 24-29 in Section D are long-answer II type questions carrying 6 marks each.
If the matrix is skew symmetric, find the values of 'a' and 'b'. VIEW SOLUTION
Question 3
Find the magnitude of each of two vectors and , having the same magnitude such that the angle between them is 60° and their scalar product is . VIEW SOLUTION
Question 4
If a * b denotes the larger of 'a' and 'b' and if = (a * b) + 3, then write the value of , where * and are binary operations. VIEW SOLUTION
The total cost C(x) associated with the production of x units of an item is given by C(x) = 0.005x3 – 0.02x2 + 30x + 5000. Find the marginal cost when 3 units are produced, where by marginal cost we mean the instantaneous rate of change of total cost at any level of output. VIEW SOLUTION
Find the differential equation representing the family of curves y = aebx+5, where a and b are arbitrary constants. VIEW SOLUTION
Question 11
If θ is the angle between two vectors , find sin θ. VIEW SOLUTION
Question 12
A black and a red die are rolled together. Find the conditional probability of obtaining the sum 8, given that the red die resulted in a number less than 4. VIEW SOLUTION
Question 13
Using properties of determinants, prove that VIEW SOLUTION
Question 14
If .
OR
If x = a (2θ – sin 2θ) and y = a (1 – cos 2θ), find when . VIEW SOLUTION
An open tank with a square base and vertical sides is to be constructed from a metal sheet so as to hold a given quantity of water. Show that the cost of material will be least when depth of the tank is half of its width. If the cost is to be borne by nearby settled lower income families, for whom water will be provided, what kind of value is hidden in this question? VIEW SOLUTION
Find the particular solution of the differential equation ex tan ydx + (2 – ex) sec2ydy = 0, give that when x = 0.
OR
Find the particular solution of the differential equation given that y = 0 when . VIEW SOLUTION
Question 20
Let Find a vector which is perpendicular to both . VIEW SOLUTION
Question 21
Find the shortest distance between the lines and VIEW SOLUTION
Question 22
Suppose a girl throws a die. If she gets 1 or 2, she tosses a coin three times and notes the number of tails. If she gets 3, 4, 5 or 6, she tosses a coin once and notes whether a 'head' or 'tail' is obtained. If she obtained exactly one 'tail', what is the probability that she threw 3, 4, 5 or 6 with the die?
Two numbers are selected at random (without replacement) from the first five positive integers. Let X denote the larger of the two numbers obtained. Find the mean and variance of X. VIEW SOLUTION
Question 24
Let A = {x ∈ Z : 0 ≤ x ≤ 12}. Show that
R = {(a, b) : a, b ∈ A, |a – b| is divisible by 4}is an equivalence relation. Find the set of all elements related to 1. Also write the equivalence class [2].
OR
Show that the function f : ℝ → ℝ defined by is neither one-one nor onto. Also, if g : ℝ → ℝ is defined as g(x) = 2x – 1, find fog(x). VIEW SOLUTION
Question 25
If , find A–1. Use it to solve the system of equations
2x – 3y + 5z = 11
3x + 2y – 4z = –5
x + y – 2z = –3.
OR
Using elementary row transformations, find the inverse of the matrix . VIEW SOLUTION
Question 26
Using integration, find the area of the region in the first quadrant enclosed by the x-axis, the line y = x and the circle x2 + y2 = 32. VIEW SOLUTION
Find the distance of the point (–1, –5, –10) from the point of intersection of the line and the plane . VIEW SOLUTION
Question 29
A factory manufactures two types of screws A and B, each type requiring the use of two machines, an automatic and a hand-operated. It takes 4 minutes on the automatic and 6 minutes on the hand-operated machines to manufacture a packet of screws 'A' while it takes 6 minutes on the automatic and 3 minutes on the hand-operated machine to manufacture a packet of screws 'B'. Each machine is available for at most 4 hours on any day. The manufacturer can sell a packet of screws 'A' at a profit of 70 paise and screws 'B' at a profit of Rs 1. Assuming that he can sell all the screws he manufactures, how many packets of each type should the factory owner produce in a day in order to maximize his profit? Formulate the above LPP and solve it graphically and find the maximum profit. VIEW SOLUTION
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