If A Equal Cos 2pi By 7 Plus I Sin 2pi By 7 Then The Quadratic Equation Whose Roots Are
(1) x2-x+2 (2) x2+x-2 (3) x2-x-2 (4) x2+x+2 Solution: a = cos 2π/7 + i sin 2π/7 ( so a7... View Article
(1) x2-x+2 (2) x2+x-2 (3) x2-x-2 (4) x2+x+2 Solution: a = cos 2π/7 + i sin 2π/7 ( so a7... View Article
Solution: Let z = x+iy iz = -y+ix z+iz = (x+iy+i(x+iy) = (x-y)+i(x+y) So the vertices of the triangle are... View Article
Solution: z = x+iy (|x|-|y| )2 ≥0 |x|2+|y|2-2|x||y| ≥0 2|x||y| ≤ |x|2+|y|2 |x|2+|y|2+2 |x| |y|≤ 2 |x|2+2 |y|2 (|x|+|y|)2 ≤... View Article
Solution: z = x+iy Given |z-i Re (z)| = |z- im(z)| |x+iy-i x| = |x+iy- y| |x+i(y- x)| = |x-y+iy|... View Article
Solution: Use w3 = 1 -1-w2 = w = = 1(w2-w4)-1(w-w2)+1(w2-w) = (w2-w)-w+w2+w2-w = 3w2-3w = 3w(w-1) Hence option (2)... View Article
Solution: Given modulus = 2 Argument is 2π/3. r = |z| = 2 x = r cos θ y =... View Article
Solution: Given = 6i(-3+3)+3i(4i+20)+1(12-60i) = 3i(20+4i)+12-60i = 60i-12+12-60i = 0+0i Comparing with x+iy, we get x= 0, y = 0... View Article
Solution: Let z = x+iy Given |z-i |+ |z+i| = k |x+iy-i |+ |x+iy+i| = k Taking modulus √(x2+(y-1)2)+ √(x2+(y+1)2)... View Article
Solution: (2z+1)/iz+1 Put z = x+iy (2(x+iy)+1)/(i(x+iy)+1) = (2x+2iy+2)/(ix-y+1) = (2x+1+2yi)/(1-y+ix) = (2x+1+2yi)(1-y-ix)/(1-y+ix)(1-y-ix) Given imaginary part is -2. Consider the... View Article
Solution: z = ((√3+i)4n+1/(1-i√3)4n) = (2(√3/2 +i/2))4n+1/(2(½ -i√3/2))4n = 24n+1 (cos π/6 + i sin π/6 )/ 24n(cos π/3 –... View Article
Solution: Given |z-4 | < | z-2 | Put z = x+iy |(x+iy)-4 | < |(x+iy)-2 | |(x-4)-iy | <... View Article
Solution: z = (1+7i)/(2-i)2 = (1+7i)/(4-4i-1) = (1+7i)/(3-4i) = (1+7i)(3+4i)/(3-4i)(3+4i) = (-25+25i)/25 = -1+i a= -1, b = 1 r... View Article
Solution: Given x = a+b, y = aα +bβ and z = aβ+bα α,β are cube roots of unity. So... View Article
Solution: Given f(x) = 4x5+5x4-8x3+5x2 +4x-34i f((-1+√3i)/2) = a+ib Let (-1+√3i)/2 = w ω3 = 1 ω+ω2 = -1 f((-1+√3i)/2)... View Article
Solution: Given (x-1)3+8 = 0 (x-1)3= -8 (x-1)= (-8)1/3 = 81/3 (-1)⅓ x-1 = 2(-1, -w, -w2) x = 1+2(-1,... View Article
Solution: Given a = cos α + i sin α b = cos β+i sinβ c = cos γ+ i... View Article
(1) 1 (2) ω or ω2 (3) ω (4) ω2 Solution: Let z = √(-1-√(-1-√(-1…∞ z = √(-1-z) Squaring we... View Article
Solution: Given z2+az+b = 0 Sum of roots, z1+z2 = -a Product of roots , z1z2 = b z2 =... View Article
Solution: Given (z-i/z+i) = π/4 arg (z-i) – arg (z+i) = π/4 Let z = x+iy arg (x+iy-i) – arg... View Article
(1) 0 (2) 1/ |z+1|2 (3) 1/|z+1|3 (4) √2/|z+1|2 Solution: Given |z| = 1 w = (z-1)/(z+1) w(z+1) = (z-1)... View Article