CBSE Class 12th Maths Answer Key 2021-22 – CBSE has conducted the class 12 mathematics exam on December 6, 2021, from 11:30 AM to 1:00 PM. Students can check CBSE Class 12 Maths question paper with answers from this page.
Ques. A relation R is defined on N Which of the following is the reflexive relation?
Ans. Correct option is (c)
Ques. A function f R ——> R defined by f(x) = 4x+3 cosx is
Ans. Neither one-one nor onto
Ques. If y = cot-1x, x<0, then
Ans. x/2 <y<x
Ques. The number of function defined from (1,2,3,4,5) —> (a,b) which are one-one is:
Ans. 0
Ques. If A = [4,2 x -1,1], then (A-2I) (A-3I) is equal to
Ans. 0
Ques. If P is a 3×3 matrix such that P = 2P+1, where P is the transpose of P, then
Ans. P = -I
Ques. If order of matrix A is 2×3, of matrix B is 3×2, and matrix C is 3×3, then which one of the following is not defined?
Ans. C(A+B’)
Ques. If A = [a,2 x 2,a] and |A3| = 27, then the value of a is
Ans. ±√7
Ques. The function f(x) = (x) is the greatest integer function that is less than or equal to x, is continuous at
Ans. 15
Ques. If y = tan-1(e2x), then dy/dx is equal to
Ans. 2e2x / 1+e4x
Ques. If y2(2-x) = x3, then (dy/dx)(1,1) is equal to
Ans. 2
Ques. The angle between the tangents to the curve y=x2-5x+6 at the points (2,0) and (3,0)
Ans. 2
Ques. The interval in which function y=x3+6×2+6 is increasing, is:
Ans. (-,-4)(0,)
Ques. The value of x for which (x-x2) is maximum, is:
Ans. ½
Ques. If the corner points of the feasible region of LPP are (0,3), (3,2) and (0,5), then the minimum value of Z=11x+7y is:
Ans. 21
Ques. The number of solutions of the system of inequations x+2y3, 3x+4y12, x0, y1 is:
Ans. 0
Ques. The number of equivalence relations in the set {1,2,3} containing the elements (1,2) and (2,1) is:
Ans. 2
Ques. Let f: RR be defined by f(x)=1x, for all xR. Then, f is:
Ans. not defined
Ques. The function f:NN is defined by f(n)=n+12, if n is odd and n2, if n is evenThe function f is:
Ans. onto but not one-one.
Ques. The value of sin-1cos 135 is:
Ans. -10
Ques. If sin-1x>cos-1x, then x should lie in the interval:
Ans. 12,1
Ques. If A=cos -sin sin cos and A+A’=I, then the value of is:
Ans. 3
Ques. The determinant y+k, y, y, y, y+k, y, y,y,y+k is equal to:
Ques. If A=[1,-2,4,2,-1,3,4,2,0] is the adjoint of a square matrix B, the B-1 is equal to:
Ans. 12A
Ques. If A=[1,-1,1,1,-1,1,1,-1,1], then A5-A4-A3+A2 is equal to:
Ans. 0
Ques. If y=e-x, then d2ydx2 is equal to:
Ans. y
Ques. If x=t2+1,y=2at, then d2ydx2 at t=a is:
Ans. -12a2
Ques. The function f(x)={x2 for x<1 and 2-x for x1} is:
Ans. not differentiable at x=1
Ques. The curve x2-xy+y=27 has tangents parallel to x-axis at:
Ans. (3,6) and (-3,-6)
Ques. A wire of length 20 cm is bent in the form of a sector of a circle. The maximum area that can be enclosed by the wire is:
Ans. 25 sq cm
Ques. The function (x-sinx) decreases for:
Ans. no value of x
Ques. If is the angle of intersection between the curves y2=4ax and ay=2x2at (a,2a), the the value of tan is:
Ans. 3/5
Ques. The maximum value of Z=3x+4y subject to the constraints x0,
Ans. 4
Ques. The feasible region of an LPP is given in the following figure. Then, the constraints of the LPP are x0, y0 and
Ans. 2x+y104 and x+2y76
Ques. If the minimum value of an objective function Z=ax+by occurs at two points (3,4) and (4,3) then:
Ans. a=b
Ques. For the following LPP, Maximise Z=3x+4y subject to constraints x-y-1, x3, x0, y0
Ans. 25
Ques. A relation r is defined on Z as: aRb if and only a2-7ab+6b2=0. Then, R is:
Ans. Reflexive but not symmetric
Ques. The value of 1!,2!,3*3!, 2*2!, 3*3!,4*4!,3!,4!,5! is :
Ans. -24
Ques. If 1, -tan, tan, 1[1, tan, -tan, 1]-1=[a,-b,b,a], then:
Ans. a=cos 2,b=sin 2
Ques. The normal to the curve 3y=6x-5×3 at the point (1,⅓) passes through the point:
Ans. (3,1)
Ques. If y=sin (2sin-1x), then (1-x2)y2 is equal to:
Ans. -xy1-4y
Ques. The volume (V) of the casted half cylinder will be:
Ans. 12r2h
Ques. The total surface area (S) of the casted half cylinder will be:
Ans. rh+r2+2rh
Ques. The volume (V) of the casted half cylinder will be:
Ans. 12r2h
Ques. The total surface area (S) of the casted half cylinder will be:
Ans. rh+r2+2rh
Ques. The total surface area S can be expressed in terms V and r as:
Ans. r+2V(+2)r
Ques. For the given half cylinder of volume V, the total surface area S is minimum, when:
Ans. (+2)V=2r3
Ques. The ratio of h:2r for S to be minimum will be equal to:
Ans. :+2
Contents
FAQs
The CBSE Class 12 term 1 mathematics examination is on 6th December 2021.
The total evaluation is of 50 marks out which 40 will be assessed via MCQ assessment and 10 will be assessed via internal marking.
CBSE has decided to include 4 units in the class 12 term 1 mathematics examination. Calculus carries 17 marks and is of the highest weightage.
The CBSE class 12th term 1 results will come out in the last week of December 2021.