A) 23
B) 24
C) 18
D) 21
(x+√(x3-1)6 + x-√(x3-1)6) = 2[6C0x6 +6C2x4(x3-1)+6C4x2(x3-1)2 +6C6(x3-1)3]
= 2[x6+15x4(x3-1)+15x2(x6-2x3+1)+(x3-1)3]
= 2[x6+15x7-15x4+15x8-30x5+15x2+x9-3x6+3(x3-1)]
Terms with even power of x =
Therefore Sum of coefficients = 2(1-15+15+15-3-1) = 24
Answer: B
A) 63/16
B) 61/16
C) 65/16
D) 32/9
sin(α-β) = 5/13
cos (α-β) = 12/13
cos(α+β) = 3/5
sin(α+β) = 4/5
tan 2α = tan[(α+β)+(α-β)]
= (4/3)+(5/12)÷(1-(4/3)×(5/12))
= 63/16
Answer: A
A) 105/4
B) 105
C) 210
D) 105/2
x2+y2 = 16
Centre = (0,0)
OA = P
Radius = 4
P = n/√2
To make the intercepts n/√2 < 4
n< 4√2
Length of intercepts = √(r2-p2)
AB = √(16-n2/2)
Length of chord BC = 2√(16-n2/2) = √(64-2n2)
Square of intercepts = (64-2n2 ), n∈N
Possible value of n = 1,2,3,4,5
Sum of square of intercepts = (64-2)+(64-8)+(64-18)+(64-32)+(64-50)
= 62+56+46+32+50
= 210
Answer: C
A) x+2sin x+sin 2x+c
B) x+2cos x+sin 2x+c
C) x-2sin x+sin 2x+c
D) x+2sin x-sin 2x+c
=
=
=
=
=
=
= x+2 sinx+sin 2x +c
Answer: A
A) 59/6
B) 57/4
C) 59/3
D) 57/6
y = x2+3x
y = 4
x2+3x= 4 = 0
x2+3x-4 = 0
x = 1 or x = -4
Area =
=
= (1/3)+(3/2)+8
= 59/6
Answer: A
A) If you are born in India then you are not citizen of India
B) If you are not citizen of India then you are not born in India
C) If you are citizen of India then you are not born in India
D) If you are citizen of India then you are born in India
Statement:
Contrapositive:
Therefore answer is if you are not citizen of India then you are not born in India.
Answer: B
A) 0
B) π/32
C) π/64
D) π/16
A =
A2 =
An =
cos 32α = 0 and sin 32α = 1
32α = π/2
α = π/64
Answer: C
A) greater than 4
B) less than 2
C) greater than 3
D) greater than 2
y2 = x-2
Differentiating we get,
2y (dy/dx) = 1
(dy/dx) = 1/2y
Slope of the line y = x is 1.
Slope of the tangent to the curve = 1/2y
1/2y = 1
→ y = 1/2
→ K = 1/2
∴ N = (9/4, 1/2)
Minimum distance = MN = perpendicular distance from point N to line y = x
= 7/4√2 which is less than 2.
Answer: B
A) √2
B) 2
C) 4
D) 4√2
Rationalise the denominator
=
=
=
= (4/2) √2+√(1+1)
= 4√2
Answer: D
A) 160
B) 175
C) 180
D) 220
Even places = 4
Odd numbers = 3
Even numbers = 6
Therefore number of numbers =
Answer: C
A) ln 1
B) ln 2
C) ln e
D) ln 4
g(f(x)) =
=
I =
=
We have
I =
Add (1) and (2)
2I =
=
Because log ab = log a + log b
2I =
Answer: A
A) 16.222
B) 8.222
C) 8.221
D) 16.221
2. 20C0 + 5.20C1+8.20C2+62.20C20
=
=
=
= 60.219+2.220
= 221(15+1)
= 221.16
Answer: D
A) 1121
B) 3210
C) 3121
D) 1520
Given numbers: 101, 102, 103, … 198, 199
91=13 × 7
HCF of 91 and a number is more than 1 means the number should be either multiple of 7 or 13.
Therefore sum of the numbers = (Numbers divisible by 7) + (Numbers divisible by 13) – (Numbers divisible by 91)
= (105+112+…+196 +( 104+117+…195 )-( 182)
= (14/2)[105+196]+(8/2)[104+195]-182
= 7(301)+4(299)-182
= 2107+1196-182
= 3121
Answer: C
A) 49
B) 48
C) 45
D) 40
Let the remaining two variates be x and y
Given mean = 8
(x+y+2+4+10+12+14)/7 = 8
x+y+42 = 56
x+y = 14 ..(1)
Given variance = 16
[(x2+y2+4+16+100+144+196)/7] – 82 = 16
(x2+y2+460)/7 = 80
(x2+y2+460) = 560
(x2+y2) = 100 ..(2)
(x+y)2-2xy = 100
Substitute (1) in above equation
142-2xy = 100
196-2xy = 100
2xy = 96
xy = 48
Answer: B
A) 4
B) 3
C) 2
D) 5
x2-2x+2 = 0
x2-2x+1+1 = 0
(x-1)2 = -1
(x-1) = ±i
x = 1+i or 1-i
Let α = 1+i
β = 1-i
(α/β) = (1+i)/(1-i)
= (1+i)2/2
= (1+i2+2i)/2
= (1-1+2i)/2
= i
(α/β)n = in = 1
Least value of n is 4.
Answer: A
A) 1/2
B) 1/4
C) 1/16
D) 1
(x2+1)2dy/dx + 2x(x2+1)y = 1
dy/dx +Py = Q
P = 2x/x2+1
Q = 1/(x2+1)2
I.F =
= 1+x2
The general solution of linear differential equation is
y.(I.F) =
y(1+x2) =
= tan-1 x+C
At x = 0, y = 0
0(1) = tan-10+C
C = 0
y.(x2+1) = tan-1x
put x = 1
y.(2) = tan-11
y.(2) = π/4
y = π/8
(1/4)y = π/32
i.e √a = ¼
a = 1/16
Answer: C
A) f(x)
B) 2f(x)
C) -2f(x)
D) [f(x)]2
f(x) =
f(2x/1+x2) =
=
=
=
= 2 f(x)
Answer: B
A)
B)
C)
D)
=
cx-y-z = 0
-cx+y-cz = 0
x+y-cz = 0
A) 1/2
B) -1
C) 2
D) 0
For non trivial solutions,
c(-c+c) +1(c2+c)-1(-c-1) = 0
c2+c+c+1 = 0
(c+1)2 = 0
c+1 = 0
c = -1
Answer: B
A) x-(π/6)
B) x+(π/6)
C) 2x-(π/6)
D) 2x-(π/3)

2y = [(π/2) -(π/3)+x]2
2y = [(π/6)-x]2
Differentiating we get,
2 dy/dx = 2[(π/6)-x](-1)
dy/dx = x-(π/6)
Answer: A
A) S1 = {-2,-1} S2 = {0}
B) S1 = {-2,1} S2 = {0}
C) S1 = {-2,1} S2 = {-1}
D) S1 = {-2,2} S2 = {0}
y = 9x4+12x3-36x2-25
dy/dx = 36x3 + 36x2-72x
= 36x(x2+x-2)
= 36x(x2+2x-x-2)
= 36x(x+2)(x-1)
Critical points are 0,-2,1
At {-2,1} -> points of minima
{0} -> points of maxima.
Answer: B
A) Increasing in (0, 1) and decreasing in (1, 2)
B) Decreasing in (0, 1) and increasing in (1, 2)
C) Increasing in (0, 2)
D) Decreasing in (0, 2)
Given f’’(x) >0, x ∈(0,2)
i.e f’(x) is an increasing function
f(x) = f(x)+f(2-x)
f’(x) = f’(x)-f’(2-x)
f(x) is increasing (x) > 0
f’(x)-f’(2-x) >0
f’(x) > f’(2-x)
x > 2-x
2x > 2
x>1
i.e x ∈ (1,2)
f(x) is decreasing (x) < 0
f’(x)-f’(2-x) <0
f’(x) < f’(2-x)
x < 2-x
2x < 2
x <1
i.e x ∈ (0,1)
Answer: B
A) 9x2 + 8y2+8y = 16
B) 8x2 + 9y2+9y = 16
C) 9x2 + 8y2-8y = 16
D) 8x2 + 9y2-9x = 16
Given AB+AC+BC = 4
1+
√(x2+y2)2 = (3-√(x2+(y-1)2)2
x2+y2 = 9+x2+y2-2y+1-6√(x2+(y-1)2)
3√(x2+(y-1)2) = 5-y
9(x2+(y-1)2 = (5-y)2
9x2+8y2-8y = 16
Answer: C
A) 1st, 2nd and 4th quadrants
B) 1st and 2nd quadrants
C) 4th quadrants
D) 1st quadrants
3x+5y = 15 is the equation of the straight line.
If x = y
3x+5x = 15
8x = 15
x = 15/8
y = 15/8
P(15/8, 15/8) lies in 1st quadrant.
If x = -y
3x-5x = 15
-2x = 15
x = -15/2
y = 15/2
Q(-15/2, 15/2) lies in 2nd quadrant.
Answer: B
A) (2, 3)
B) (3, 4)
C) (4, 5)
D) (1, 2)
Let A be (2,-1,4).
Direction ratio of AB = (10λ-5, -7λ+3, λ-4)
Drs of given line = (10, -7, 1)
10(10λ-5)-7(-7λ+3)+(λ -4) = 0
100λ -50+49-21+λ-4 = 0
150λ = 75
λ = 1/2
Point B (2, -3/2, 1/2)
Length AB = 5/√2
= 3.53
Answer: B
A) x-y-z = 0
B) 2x-z = 0
C) x+2z-1 = 0
D) x-z-1 = 0
Required equation of the plane is (2x-y-4)+λ(y+2z-4) = 0
Given it pass through (1,1,0)
(2-1-4)+λ(1+0-4) = 0
λ= -1
(2x-y-4)-(y+2z-4) = 0
2x-2y-2z = 0
x-y-z = 0
Answer: A
A) 4
B) 10
C) 9
D) 12
Given equation is |√x-2|+√x(√x-4)+2 = 0, (x>0)
Put √x = t
|t-2|+t(t-4)+2 = 0
If t ≥2
t-2+t2-4t+2 = 0
t2-3t = 0
t(t-3) = 0
t = 3 or t = 0
t = 0 not possible
if t = 3, x = 9
If t < 2
2-t+t2-4t+2 = 0
t2-5t+4 = 0
t = 1 or t = 4
t = 4 not possible
so t = 1
x = 1
Sum of solution = 9+1 = 10
Answer: B
A) 2/17
B) 64/17
C) 128/17
D) 4/17
The equation of the ellipse 4x2+y2 = 8
dy/dx = -4x/y
The tangent at (1,2) and (a,b) are perpendicular
(-y/2)(-4a/b) = -1
b = -8a ..(i)
(a,b) is on the ellipse.
4a2+b2 = 8 [from eq(i)]
4a2+64a2 = 8
a2 = 8/68 = 2/17
Answer: A
A) √3/2
B) √(3/2)
C) 3√6
D) √6
The vector perpendicular to given vectors is
So
Projection of vector b in direction of vector a =
=
= 2-6+1/√6
= 3/√6
= √(3/2)
Answer: B
A) tan-1(9/5√10)
B) sin-1(9/5√10)
C) tan-1(9/15)
D) cos-1(9/5√10)
α = cos-1(3/5) = tan-1(4/3)
β = tan-1 (1/3)
α-β = tan-1(4/3) – tan-1 (1/3)
=
=
= tan-1(9/13)
=
= sin-1(9/√250)
= sin-1(9/5√10)
Answer: B
Video Lessons – Maths Paper April




JEE Main 2019 April Maths Paper with Solutions
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