हिंदी

If |z1| = 1(z1 ≠ –1) and z2 = z1-1z1+1, then show that the real part of z2 is zero.

Advertisements
Advertisements

प्रश्न

If |z1| = 1(z1 ≠ –1) and z2 = `(z_1 - 1)/(z_1 + 1)`, then show that the real part of z2 is zero.

योग
Advertisements

उत्तर

Let z1 = x + yi

|z1| = `sqrt(x^2 + y^2)` = 1   ......[Given that |z1| = 1]

⇒ x2 + y2 = 1  ......(i)

Now z2 = `(z_1 - 1)/(z_1 + 1)`

= `(x + yi - 1)/(x + yi + 1)`

= `((x + 1) + y"i")/((x + 1) + y"i")`

= `((x - 1) + yi)/((x + 1) + yi) xx (x + 1 - yi)/(x + 1 - yi)`

= `((x - 1)(x + 1) - y(x - 1)i + y(x + 1)i - y^2i^2)/((x + 1)^2 - y^2i^2)`

= `(x^2 - 1 + yi(x + 1 - x + 1) + y^2)/(x^2 + 1 + 2x + y^2)`

= `((x^2 + y^2 - 1) + 2yi)/(x^2 + y^2 + 2x + 1)`

= `((1 - 1))/(x^2 + y^2 + 2x + 1) + (2y)/(x^2 + y^2 + 2x + 1) "i"`

= `0 + (2y)/(x^2 + y^2 + 2x + 1) "i"`

Hence, the real part of z2 is 0.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 5: Complex Numbers and Quadratic Equations - Exercise [पृष्ठ ९२]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 5 Complex Numbers and Quadratic Equations
Exercise | Q 17 | पृष्ठ ९२

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

If (a + ib) (c + id) (e + if) (g + ih) = A + iB, then show that (a2 + b2) (c2 + d2) (e2 + f2) (g2 + h2) = A2 + B2.


If `((1+i)/(1-i))^m` = 1, then find the least positive integral value of m.


Show that 1 + i10 + i20 + i30 is a real number.


Find the value of i + i2 + i3 + i4 


Simplify the following and express in the form a + ib:

`(1 + 2/i)(3 + 4/i)(5 + i)^-1`


Simplify the following and express in the form a + ib:

`(5 + 7"i")/(4 + 3"i") + (5 + 7"i")/(4 - 3"i")`


Find the value of: x3 – 3x2 + 19x – 20, if x = 1 – 4i


Write the conjugates of the following complex number:

`-sqrt(-5)`


Write the conjugates of the following complex number:

5i


Evaluate: `("i"^37 + 1/"i"^67)`


Find the value of `("i"^6 + "i"^7 + "i"^8 + "i"^9)/("i"^2 + "i"^3)`


Find the value of x and y which satisfy the following equation (x, y∈R).

`(x+ 1)/(1 + "i") + (y - 1)/(1 - "i")` = i


Find the value of x and y which satisfy the following equation (x, y∈R).

If x + 2i + 15i6y = 7x + i3 (y + 4), find x + y


Select the correct answer from the given alternatives:

If n is an odd positive integer then the value of 1 + (i)2n + (i)4n + (i)6n is :


Answer the following:

Simplify the following and express in the form a + ib:

`5/2"i"(-4 - 3"i")`


Answer the following:

Solve the following equation for x, y ∈ R:

`(x + "i"y)/(2 + 3"i")` = 7 – i


Answer the following:

Show that `(1 - 2"i")/(3 - 4"i") + (1 + 2"i")/(3 + 4"i")` is real


If z1, z2, z3 are complex numbers such that `|z_1| = |z_2| = |z_3| = |1/z_1 + 1/z_2 + 1/z_3|` = 1, then find the value of |z1 + z2 + z3|.


What is the value of `(i^(4n + 1) -i^(4n - 1))/2`?


What is the locus of z, if amplitude of z – 2 – 3i is `pi/4`?


The number `(1 - i)^3/(1 - i^2)` is equal to ______.


The sum of the series i + i2 + i3 + ... upto 1000 terms is ______.


The point represented by the complex number 2 – i is rotated about origin through an angle `pi/2` in the clockwise direction, the new position of point is ______.


If a + ib = c + id, then ______.


The complex number z which satisfies the condition `|(i + z)/(i - z)|` = 1 lies on ______.


If the least and the largest real values of α, for which the equation z + α|z – 1| + 2i = 0 `("z" ∈ "C" and "i" = sqrt(-1))` has a solution, are p and q respectively; then 4(p2 + q2) is equal to ______.


Let |z| = |z – 3| = |z – 4i|, then the value |2z| is ______.


Let z be a complex number such that `|(z - i)/(z + 2i)|` = 1 and |z| = `5/2`. Then the value of |z + 3i| is ______.


Find the value of `(i^592 + i^590 + i^588 + i^586 + i^584)/ (i^582 + i^580 + i^578 + i^576 + i^574)`


Simplify the following and express in the form a+ib.

`(3"i"^5 + 2"i"^7 + "i"^9)/("i"^6 + 2"i"^8 + 3"i"^18)`


Simplify the following and express in the form a + ib.

`(3i^5 + 2i^7 + i^9)/(i^6 + 2i^8 + 3i^18)`


Simplify the following and express in the form a+ib.

`(3i^5 + 2i^7 + i^9)/(i^6 + 2i^8 + 3i^18)`


i2 + i3 + ... + i4000 =


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×