Grade 12 Maths Practice Exam
Grade 12 Maths Practice Exam
Grade 12 Maths Practice Exam
[ cosα
2. If A= sinα
−sinα
cosα ]
,then A+AT=I,if the value of α is
π π 3π
a) 6 b) 3 c) 2 d) π
3. The value(s) of k,if area of triangle is 4 sq unit and vertices are (k,0),(4,0),(0,2)
a) 0 b) 8 c) 0,8 d) 0 ,-8
( ) ( ) ( )
2
d3 y d2 y dy 4
−3 +2 = y 4 are
dx 3
dx 2
dx
a) 1, 4 b) 3, 4 c) 2, 4 d) 3, 2
dy
10.Integrating factor of the differential equation cos x dx + y sinx = 1 is
14. A line makes angle α , β∧γ with the co-ordinate axes. If α + β=90 ° , then γ is equal to
a) 0 b) 90° c) 180 ° d) None of these
15. The vector equation of the symmetrical form of equation of straight line
x−5 y+ 4 z−6
3
=
7
=
2
is
a) r⃗ =( 3^i+ 7^j+ 2^k ) + μ(5^i+ 4^j−6^k) b) r⃗ =( 5^i+ 4^j−6^k ) + μ (3^i+ 7^j+ 2^k)
c) r⃗ =( 5^i−4^j−6^k ) + μ(3^i−7^j−2^k ) d) r⃗ =( 5^i−4^j+ 6^k ) + μ ( 3^i+ 7^j+ 2^k)
16. Which of the following statement is false?
a) The feasible region is always a concave region.
b) The maximum (or minimum) solution of the objective function occurs at the vertex
of the feasible region.
c) If two corner points produce the same maximum (or minimum) value of the objective
function, then every point on the line segment joining these points will also give the
same maximum (or minimum) value.
d) None of these.
17. Corner points of the feasible region determined by the system of linear constraints are (0,
3), (1, 1) and (3, 0). Let Z = px +qy, where p, q > 0. Condition on p and q, so that the
minimum of Z occurs at (3, 0) and (1, 1) is
q
a) p = 2q b)p = 2 c) p = 3q d) p = q
,
then A, B, C are mutually exclusive events.
Reason (R) : If P (A∪ B ∪ C ¿= P (A) + P (B) + P (C), then A, B, C are mutually
exclusive events.
SECTION – B
( This section comprises of very short answer type- questions (VSA) of 2 marks each)
21. Check whether the relation R defined on the set A = {1, 2, 3, 4, 5, 6} as R = {(a, b): b = a + 1} is
reflexive, symmetric or transitive. (OR)
Find the integral of sin(ax+b)cos(ax+b)
23. Find a unit vector perpendicular to each of the vectors a⃗ and b⃗ where
a⃗ = 5^i+ 6^j−2^k ∧⃗b=7^i+ 6^j+ 2^k
SECTION – C
( This section comprises of short answer type questions (SA) of 3 marks each)
28. ∫ ¿ x +2∨¿ ¿
−5
( This section comprises of long answer – type questions (LA) of 5 marks each)
32. Using integration, find the area bounded by the curve x2 = 4y and the line x = 4y -2.(OR)
Find the area of the region bounded by the parabola y=x2 and y = ¿ x∨¿
33. If A = {1, 2, 3, .. ,9} and R is the relation in A × A defined by (a , b) R(c, d), if a + d = b + c for (a,b), (c,
d) in A × A. Prove that R is an equivalence relation. Also, obtain the equivalence class [(2, 5)].
34. Find the coordinates of the foot of perpendicular drawn from the point A (- 1, 8, 4) to the line joining the
points B(0, – 1, 3) and C(2, – 3, – 1). Hence, find the image of the point A in the line BC. (OR)
Find the vector p⃗ which is perpendicular to both α⃗ = 4î + 5ĵ – k̂ and β⃗ = î – 4ĵ + 5k̂ and p⃗ . q⃗ =
SECTION – E
( This section comprises of 3 case – study/ passage – based questions of 4 marks each with
two sub-parts. First two case study questions have three sub-parts (i), (ii), (iii) of marks 1,
1, 2 respectively. The third case study question has two sub-parts of 2 marks each)
36. Case – Study 1 :
Two motorcycles A and B are running at the speed more than allowed speed on the road
^ ^j−k^ )∧⃗r =3^i+ 3^j+ μ ( 2^i + ^j+ k^ ) ,respectively .
along the lines r⃗ =λ ( i+2
37. In an office three employees Vinay, Sonia and lqbal process incoming copies of a
certain form. Vinay process 50 % of the forms, Sonia processes 20 % abd lqbal the
remaining 30 % of the forms. Vinay has an error rate of 0.06, Sonia has an error rate of 0.04
and lqbal has an error rate of 0.03.
Based on the above information, answer the following questions.
i) What is the conditional probability that an error is committed in processing given that
Sonia processed the form.
ii)What is the probability that Sonia processed the form and committed an error.
iii) Let A be the event of committing an error in processing the form and let E1, E2 and E3
be the events that Vinay, Sonia and lqbal processed the form. Find the value of
3
∑ P ( Ei| A ¿ . ¿
i=1
dy f (x , y ) dy
( y)
38. If the equation is of the form dx = g ( x , y ) ∨ dx =F x , where f(x, y), g(x, y) are
dy dv
homogeneous functions of the same degree in x and y, and dx =v +x dx , so that the
dependent variable y is changed to another variable v and then apply variable separable
method.
Based on the above information, answer the following questions.
2 dy 2 2
i) Find the general solution of x dx =x + xy+ y .
dy 2 2
ii) What is the solution of the differential equation 2xy dx =x +3 y ?