St. Britto Hr. Sec. School - Madurai
12th Maths Important 1 Mark Question Paper-Aug 2020
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The distance between the planes x + 2y + 3z + 7 = 0 and 2x + 4y + 6z + 7 = 0
\(\frac { \sqrt { 7 } }{ 2\sqrt { 2 } } \)
\(\frac{7}{2}\)
\(\frac { \sqrt { 7 } }{ 2 } \)
\(\frac { 7 }{ 2\sqrt { 2 } } \)
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Bala Add questions
test
option MS
test
test
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The solution of \(\frac{dy}{dx}\)+y cot x=sin 2x is
y sin x=\(\frac{2}{3}\) sin3 x+c
y sec x=\(\frac{x^2}{2}\)+c
y sin x =c+x
2y sin x=sin x-\(\frac{sin \space 3x}{3}\)+c
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The value of \({ \left| \overset { \rightarrow }{ a } +\overset { \rightarrow }{ b } \right| }^{ 2 }+{ \left| \overset { \rightarrow }{ a } -\overset { \rightarrow }{ b } \right| }^{ 2 }\) is
\(2\left( { \left| \overset { \rightarrow }{ a } \right| }^{ 2 }+{ \left| \overset { \rightarrow }{ b } \right| }^{ 2 } \right) \)
4 \(\overset { \rightarrow }{ a } .\overset { \rightarrow }{ b } \)
\(2\left( { \left| \overset { \rightarrow }{ a } \right| }^{ 2 }-{ \left| \overset { \rightarrow }{ b } \right| }^{ 2 } \right) \)
4 \({ \left| \overset { \rightarrow }{ a } \right| }^{ 2 }{ \left| \overset { \rightarrow }{ b } \right| }^{ 2 }\)
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Let a > 0, b > 0, c >0. h n both th root of th quatlon ax2+b+C= 0 are
real and negative
real and positive
rational numb rs
none
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The number of vectors of unit length perpendicular to the vectors \(\left( \overset { \wedge }{ i } +\overset { \wedge }{ j } \right) \) and \(\left( \overset { \wedge }{ j } +\overset { \wedge }{ k } \right) \)is
1
2
3
∞
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The differential equation representing the family of curves y = Acos(x + B), where A and B are parameters, is
\(\frac{d^2y}{dx^2}-y=0\)
\(\frac{d^2y}{dx^2}+y=0\)
\(\frac{d^2y}{dx^2}=0\)
\(\frac{d^2x}{dy^2}=0\)
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Consider the vectors \(\vec { a } ,\vec { b } ,\vec { c } ,\vec { d } \) such that \((\vec { a } \times \vec { b } )\times (\vec { c } \times \vec { d } )\) = \(\vec { 0 } \) Let \({ P }_{ 1 }\) and \({ P }_{ 2 }\) be the planes determined by the pairs of vectors \(\vec { a } ,\vec { b } \) and \(\vec { c } ,\vec { d } \) respectively. Then the angle between \({ P }_{ 1 }\) and \({ P }_{ 2 }\) is
0°
45°
60°
90°
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If A =\(\left( \begin{matrix} cosx & sinx \\ -sinx & cosx \end{matrix} \right) \) and A(adj A) =\(\lambda \) \(\left( \begin{matrix} 1 & 0 \\ 0 & 1 \end{matrix} \right) \) then \(\lambda \) is
sinx cosx
1
2
none
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The solution of \(\frac{dy}{dx}\)+ p(x)y=0 is
y = ce ∫ pdx
y = ce − ∫ pdx
x = ce − ∫ pdy
x = ce ∫ pdy
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The differential equation of the family of parabolas y2 =4ax is
2y = x(\(\frac{dy}{dx}\))
y = 2x(\(\frac{dy}{dx}\))
y = 2x2(\(\frac{dy}{dx}\))
y2 = 2x(\(\frac{dy}{dx}\))
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If the foci of the ellipse \(\frac { { x }^{ 2 } }{ 16 } +\frac { { y }^{ 2 } }{ { b }^{ 2 } } \) = 1 and the hyperbola \(\frac { { x }^{ 2 } }{ 144 } -\frac { { y }^{ 2 } }{ 81 } =\frac { 1 }{ 25 } \) coincide then b2 is
1
5
7
9
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If z=1-cosθ + i sinθ, then |z| =
2 sin\(\frac { 1 }{ 3 } \)
2 cos\(\frac { \theta }{ 2 } \)
2|sin\(\frac { \theta }{ 2 } \)|
2|cos\(\frac { \theta }{ 2 } \)|
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Distance from the origin to the plane 3x - 6y + 2z + 7 = 0 is
0
1
2
3
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The change in the surface area S = 6x2 of a cube when the edge length varies from x0 to x0+ dx is
12 x0+ dx
12 x0 dx
6x0 dx
6x0 + dx
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\(cot\left( \cfrac { \pi }{ 4 } -{ 2cot }^{ -1 }3 \right) \)
7
6
5
none
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If the vector \(\overset { \wedge }{ i } +\overset { \wedge }{ j } +\overset { \wedge }{ 2k } \), \(\overset { \wedge }{ -i } +\overset { \wedge }{ 2k } \) and \(2\overset { \wedge }{ i } +x\overset { \wedge }{ j } -y\overset { \wedge }{ k } \) are mutually orthogonal, then the values of x, y, z are
(10, 4, 1)
(-10, 4, 1)
(-10, -4, \(\frac { 1 }{ 2 } \))
(-10, 4, \(\frac { 1 }{ 2 } \))
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If \(\alpha \) and \(\beta \) are the roots of x2+x+1=0, then \({ \alpha }^{ 2020 }+{ \beta }^{ 2020 }\)
-2
-1
1
2
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If z=cos\(\frac { \pi }{ 4 } \)+i sin\(\frac { \pi }{ 6 } \), then
|z| =1, arg(z) =\(\frac { \pi }{ 4 } \)
|z| =1, arg(z) =\(\frac { \pi }{ 6 } \)
|z|=\(\frac { \sqrt { 3 } }{ 2 } \), arg(z)=\(\frac { 5\pi }{ 24 } \)
|z| =\(\frac { \sqrt { 3 } }{ 2 } \), arg (z) =tan-1\(\left( \frac { 1 }{ \sqrt { 2 } } \right) \)
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If sin-1 x+sin-1 y+sin-1 z= \(\frac{3π}{2}\), the value of x +y +z −\(\frac{9}{x^{101} + y^{101} + z^{101}}\) is
0
1
2
3
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The value of tan \(\left( { cos }^{ -1 }\cfrac { 3 }{ 5 } +{ tan }^{ -1 }\cfrac { 1 }{ 4 } \right) \) is ______
\(\cfrac { 19 }{ 8 } \)
\(\cfrac { 8 }{ 19 } \)
\(\cfrac { 19 }{ 12 } \)
\(\cfrac { 3 }{ 4 } \)
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In a homogeneous system if \(\rho\) (A) =\(\rho\)([A|0]) < the number of unknouns then the system has ________
trivial solution
only non - trivial solution
no solution
trivial solution and infinitely many non - trivial solutions
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The general solution of x \(\frac{dy}{dx}\)=y is _________.
y=cx
x2+y2=c
x2-y2=c
y=cx
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Which one is the contrapositive of the statement (pVq)⟶r?
ㄱr➝(ㄱp∧ㄱq)
ㄱr⟶(p∨q)
r⟶(p∧q)
p⟶(q∨r)
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If x3+12x2+10ax+1999 definitely has a positive root, if and only if
a≥0
a>0
a<0
a≤0
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If A = \(\left[ \begin{matrix} \frac { 3 }{ 5 } & \frac { 4 }{ 5 } \\ x & \frac { 3 }{ 5 } \end{matrix} \right] \) and AT = A−1 , then the value of x is
\(\frac { -4 }{ 5 } \)
\(\frac { -3 }{ 5 } \)
\(\frac { 3 }{ 5 } \)
\(\frac { 4 }{ 5 } \)
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In the non - homogeneous system of equations with 3 unknowns if \(\rho\)(A) = \(\rho\)([AIB]) = 2, then the system has _______
unique solution
one parameter family of solution
two parameter family of solutions
in consistent
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If f (x, y) = x3 + y3 then \(\frac { \partial f }{ \partial { x } } \) at x = 2, y = 3 is
-15
15
-9
16
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Which one of the following is incorrect? For any two propositions p and q, we have
¬ (p∨q) ≡ ¬ p ∧ ¬q
¬ ( p∧ q)≡¬p ∨ ¬q
¬ (p ∨ q)≡¬p∨¬q
¬(¬p)≡ p
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If ATA−1 is symmetric, then A2 =
A-1
(AT)2
AT
(A-1)2
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Let A = \(\left[ \begin{matrix} 2 & -1 & 1 \\ -1 & 2 & -1 \\ 1 & -1 & 2 \end{matrix} \right] \) and 4B = \(\left[ \begin{matrix} 3 & 1 & -1 \\ 1 & 3 & x \\ -1 & 1 & 3 \end{matrix} \right] \). If B is the inverse of A, then the value of x is
2
4
3
1
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A random variable X has binomial distribution with n = 25 and p = 0.8 then standard deviation of X is
6
4
3
2
-
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If x+y=k is a normal to the parabola y2 =12x, then the value of k is
3
-1
1
9
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In an ellipse, the distance between its foci is 6 and its minor axis is 8, then e is
\(\frac { 4 }{ 5 } \)
\(\frac { 1 }{ \sqrt { 52 } } \)
\(\frac { 3 }{ 5 } \)
\(\frac { 1 }{ 2 } \)
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If a=cosθ + i sinθ, then \(\frac { 1+a }{ 1-a } \) =
cot \(\frac { \theta }{ 2 } \)
cot θ
i cot \(\frac { \theta }{ 2 } \)
i tan\(\frac { \theta }{ 2 } \)
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-
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The augmented matrix of a system of linear equations is \(\left[ \begin{matrix} 1 \\ \begin{matrix} 0 \\ 0 \end{matrix} \end{matrix}\begin{matrix} 2 \\ \begin{matrix} 1 \\ 0 \end{matrix} \end{matrix}\begin{matrix} 7 \\ \begin{matrix} 4 \\ \lambda -7 \end{matrix} \end{matrix}\begin{matrix} 3 \\ \begin{matrix} 6 \\ \mu +5 \end{matrix} \end{matrix} \right] \). The system has infinitely many solutions if
λ = 7, μ ≠ -5
λ = 7, μ = 5
λ ≠ 7, μ ≠ -5
λ = 7, μ = -5
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If A = [2 0 1] then the rank of AAT is ______
1
2
3
0
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The solution of the differential equation \(\frac{dy}{dx}=\frac{y}{x}+\frac{ϕ\left(\frac{y}{x}\right)}{ϕ'\left(\frac{y}{x}\right)}\) is
\(xϕ\left(\frac{y}{x}\right)=k\)
\(ϕ\left(\frac{y}{x}\right)=kx\)
\(yϕ\left(\frac{y}{x}\right)=k\)
\(ϕ\left(\frac{y}{x}\right)=ky\)
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If |z|=1, then the value of \(\cfrac { 1+z }{ 1+z } \) is
z
\(\bar { z } \)
\(\cfrac { 1 }{ 2 } \)
1
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If u = y sin x then \(\frac { { \partial }^{ 2 }u }{ \partial x\partial y } \) = _______________.
cos x
cos y
sin x
0
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The coordinates of the point where the line \(\vec { r } =(6\hat { i } -\hat { j } -3\hat { k } )+t(\hat {- i } +4\hat { j } )\) meets the plane \(\vec { r } =(\hat { i } +\hat { j } -\hat { k } )\) = 3 are
(2,1,0)
(7,1,7)
(1,2,6)
(5,-1,1)
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If the function f(x)sin-1(x2-3), then x belongs to
[-1,1]
[\(\sqrt2\),2]
\(\\ \\ \\ \left[ -2,-\sqrt { 2 } \right] \cup \left[ \sqrt { 2 } ,2 \right] \)
\(\left[ -2,-\sqrt { 2 } \right] \cap \left[ \sqrt { 2 } ,2 \right] \)
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If sin-1 \(\frac{x}{5}+ cot^{-1}\frac{5}{4}=\frac{\pi}{2}\), then the value of x is
4
5
2
3
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The value of \(\frac { (cos{ 45 }^{ 0 }+isin{ 45 }^{ 0 })^{ 2 }(cos{ 30 }^{ 0 }-isin{ 30 }^{ 0 }) }{ cos{ 30 }^{ 0 }+isin{ 30 }^{ 0 } } \) is
\(\frac { 1 }{ 2 } +i\frac { \sqrt { 3 } }{ 2 } \)
\(\frac { 1 }{ 2 } -i\frac { \sqrt { 3 } }{ 2 } \)
\(-\frac { \sqrt { 3 } }{ 2 } +\frac { i }{ 2 } \)
\(\frac { \sqrt { 3 } }{ 2 } +\frac { i }{ 2 } \)
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Which of the following is not an elementary transformation?
Ri ↔️ Rj
Ri ⟶ 2Ri + Rj
Cj ⟶ Cj + Ci
Ri ⟶ Ri + Cj
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If A is a non-singular matrix then IA-1|= ______
\(\left| \frac { 1 }{ { A }^{ 2 } } \right| \)
\(\frac { 1 }{ |A^{ 2 }| } \)
\(\left| \frac { 1 }{ A } \right| \)
\(\frac { 1 }{ |A| } \)
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If \(\omega \neq 1\) is a cubic root of unity and \(\left| \begin{matrix} 1 & 1 & 1 \\ 1 & { -\omega }^{ 2 } & { \omega }^{ 2 } \\ 1 & { \omega }^{ 2 } & { \omega }^{ 2 } \end{matrix} \right| \) =3k, then k is equal to
1
-1
\(\sqrt { 3i } \)
\(-\sqrt { 3i } \)
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The area of quadrilateral formed with foci of the hyperbolas \(\frac { { x }^{ 2 } }{ { a }^{ 2 } } -\frac { { y }^{ 2 } }{ { b }^{ 2 } } =1\\ \) and \(\frac { { x }^{ 2 } }{ { a }^{ 2 } } -\frac { { y }^{ 2 } }{ { b }^{ 2 } } =-1\)
4(a2+b2)
2(a2+b2)
a2 +b2
\(\frac { 1 }{ 2 } \)(a2+b2)
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In the set Q define a⊙b= a+b+ab. For what value of y, 3⊙(y⊙5)=7?
y = \(\frac{2}{ 3}\)
y = \(\frac{-2}{ 3}\)
y =\(\frac{-3}{ 2}\)
y = 4
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If U = xy + yx then ux + u y at x = y = 1 is
0
2
1
\(\infty \)
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If A is a square matrix that IAI = 2, than for any positive integer n, |An| =
0
2n
2n
n2
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When the eccentricity of a ellipse becomes zero, then it becomes a
straight line
circle
point
parabola
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If \(\omega \neq 1\) is a cubic root of unity and \(\left( 1+\omega \right) ^{ 7 }=A+B\omega \) ,then (A,B) equals
(1,0)
(−1,1)
(0,1)
(1,1)
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If x is real and \(\frac { { x }^{ 2 }-x+1 }{ { x }^{ 2 }+x+1 } \) then
\(\frac{1}{3}\) ≤k≤
k≥5
k≤0
none
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If loge4 = 1..3868, then loge 4.01 =
1.3968
1.3898
1.3893
none
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If adj A = \(\left[ \begin{matrix} 2 & 3 \\ 4 & -1 \end{matrix} \right] \) and adj B = \(\left[ \begin{matrix} 1 & -2 \\ -3 & 1 \end{matrix} \right] \) then adj (AB) is
\(\left[ \begin{matrix} -7 & -1 \\ 7 & -9 \end{matrix} \right] \)
\(\left[ \begin{matrix} -6 & 5 \\ -2 & -10 \end{matrix} \right] \)
\(\left[ \begin{matrix} -7 & 7 \\ -1 & -9 \end{matrix} \right] \)
\(\left[ \begin{matrix} -6 & -2 \\ 5 & -10 \end{matrix} \right] \)
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If the system of equations x + 2y - 3x = 2, (k + 3) z = 3, (2k + 1) y + z = 2. is inconsistent then k is
-3, -\(\frac{1}{2}\)
-\(\frac{1}{2}\)
1
2
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If \(z-2+i\le 2\) then the greatest value of |z| is
\(\sqrt { 3 } -2\)
\(\sqrt { 3 } +2\)
\(\sqrt { 5 } -2\)
\(\sqrt { 5 } +2\)
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If z is a non zero complex number, such that 2iz2=\(\bar { z } \) then |z|is then |z| is
\(\cfrac { 1 }{ 2 } \)
1
2
3
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If w (x,y,z) = x2 (y - z) + y2 (z - x) + z2 (x - y), then \(\frac { \partial w }{ \partial x } +\frac { \partial w }{ \partial y } +\frac { \partial w }{ \partial z } \) is
xy + yz + zx
x(y + z)
y(z + x)
0
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Let A be a 3 x 3 matrix and B its adjoint matrix If |B|=64, then |A|=
±2
±4
±8
±12
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The conjugate of \(\frac { 1+2i }{ 1-(1-i)^{ 2 } } \) is _______
\(\frac { 1+2i }{ 1-(1-i)^{ 2 } } \)
\(\frac { 5 }{ 1-(1-i)^{ 2 } } \)
\(\frac { 1-2i }{ 1+(1+i)^{ 2 } } \)
\(\frac { 1+2i }{ 1+(1-i)^{ 2 } } \)
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If x < 0, y < 0 such that xy = 1, then tan-1(x) + tan-l(y) =_____
\(\cfrac { \pi }{ 2 } \)
\(\cfrac { -\pi }{ 2 } \)
\(-\pi \)
none
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The angle between the vector \(3\overset { \wedge }{ i } +4\overset { \wedge }{ j } +\overset { \wedge }{ 5k } \) and the z-axis is
30o
60o
45o
90o
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The number of real numbers in [0,2π] satisfying sin4x-2sin2x+1 is
2
4
1
∞
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Four buses carrying 160 students from the same school arrive at a football stadium. The buses carry, respectively, 42, 36, 34, and 48 students. One of the students is randomly selected. Let X denote the number of students that were on the bus carrying the randomly selected student One of the 4 bus drivers is also randomly selected. Let Y denote the number of students on that bus. Then E[X] and E[Y] respectively are
50,40
40,50
40.75,40
41,41
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If \({ tan }^{ -1 }\left\{ \cfrac { \sqrt { 1+{ x }^{ 2 } } -\sqrt { 1-{ x }^{ 2 } } }{ \sqrt { 1+{ x }^{ 2 } } +\sqrt { 1-{ x }^{ 2 } } } \right\} =\alpha \) then x2 =
\(sin2\alpha \)
\(sin\alpha \)
\(cos2\alpha \)
\(cos\alpha \)
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z1,z3 and z3 are complex number such that z1+z2+z3=0 and |z1|=|z2|=|z3|=1 then z12+z22+z23 is
3
2
1
0