Given z1= sqrt 2 (cos(3pi/4)+ i sin (3pi/4)) and z2= (cos(pi/2)+ i sin (pi/2)), what is the value of z1-z2?
A- cos(0)+isin(0)
B-cos(0)-isin(0)
C- cos(pi)+isin(pi)
D- cos(pi)-isin(pi)

Given z1 sqrt 2 cos3pi4 i sin 3pi4 and z2 cospi2 i sin pi2 what is the value of z1z2 A cos0isin0 Bcos0isin0 C cospiisinpi D cospiisinpi class=

Respuesta :

Answer:

Answer is B

Step-by-step explanation:

The value of z₁ - z₂ is C- cos(pi)+isin(pi)

Since z₁ = √2[cos(3π/4) + isin(3π/4)] and z₂ = [cos(π/2) + isin(π/2)]

z₁ - z₂ = √2[cos(3π/4) + isin(3π/4)] - ([cos(π/2) + isin(π/2)])

= √2[cos(3π/4)] + i√2[sin(3π/4)] - cos(π/2) - isin(π/2)

= √2[cos(3π/4)] - cos(π/2) + i√2[sin(3π/4)] - isin(π/2)

Since 3π/4 = 3π/4 × 180°/π = 135° and π/2 = π/2 × 180°/π = 90°,

So,

z₁ - z₂ = √2[cos(3π/4)] - cos(π/2) + i√2[sin(3π/4)] - isin(π/2)

z₁ - z₂ = √2[cos135°] - cos90° + i√2[sin135°] - isin90°

z₁ - z₂ = √2[cos(180° - 45°) - cos90° + i(√2[sin(180° - 45°)] - sin90°)

z₁ - z₂ = √2[-cos45°] - cos90° + i√2[sin45°] - isin90°

cos45° = sin45° = 1/√2 and sin90° = 1 and cos90° = 0.

So,

z₁ - z₂ = √2[-1/√2 ] - 0 + i(√2[1/√2 ] - 1)

z₁ - z₂ = - 1 - 0 + i(1 - 1)

z₁ - z₂ = - 1 + i0

z₁ - z₂ = - 1

So, the magnitude of |z₁ - z₂| = |- 1| = 1 = r

It's argument tanθ = sinθ/cosθ, since sinθ = 0 and cosθ = -1

tanθ = 0/-1 = -0

tanθ = -0 ⇒ tan(π - θ) = 0

Taking inverse tan of both sides, we have

π - θ = tan⁻¹(0)

π - θ = 0

π = θ

Since z₁ - z₂ = r[cosθ + isinθ]  and r = 1 and θ = π, then

z₁ - z₂ = r[cosθ + isinθ]

z₁ - z₂ = 1[cosπ + isinπ]

z₁ - z₂ = cosπ + isinπ

The value of z₁ - z₂ is C- cos(pi)+isin(pi)

Learn more about complex numbers here:

https://brainly.com/question/17553022

ACCESS MORE
ACCESS MORE
ACCESS MORE
ACCESS MORE