मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

Express the following complex numbers in polar form and exponential form: 1+7i(2-i)2

Advertisements
Advertisements

प्रश्न

Express the following complex numbers in polar form and exponential form:

`(1 + 7"i")/(2 - "i")^2`

बेरीज
Advertisements

उत्तर

Let z = `(1 + 7"i")/(2 - "i")^2`

= `(1 + 7"i")/(4 - 4"i" + "i"^2)`

= `(1 + 7"i")/(4 - 4"i" - 1)`

= `(1 + 7"i")/(3 - 4"i")`

= `((1 + 7"i")(3 + 4"i"))/((3 - 4"i")(3 + 4"i"))`

= `(3 + 4"i" + 21"i" + 28"i"^2)/(9 - 16"i"^2)`

= `(25"i" + 3 + 28(-1))/(9 - 16(-1))`

= `(25"i" - 25)/25`

∴ z = – 1 + i

∴ a = – 1, b = 1

∴ |z| = r

= `sqrt("a"^2 + "b"^2)`

= `sqrt((-1)^2 + 1^2)`

= `sqrt(2)`

Here, (–1, 1) lies in 2nd quadrant

θ = amp (z)

= `pi + tan^-1("b"/"a")`

= `pi + tan^-1(1/(-1))`

= π + tan–1(–1)

= π – tan–1(1)

= `pi - pi/4`

= `(3pi)/4`

∴ θ = 135° = `(3pi)/4`

∴ the polar form of z = r (cos θ + i sin θ)

= `sqrt(2) (cos 135^circ +  "i"  sin 135^circ)`

= `sqrt(2)(cos  (3pi)/4 + "i"  sin  (3pi)/4)`

The exponential form of z = re= `sqrt(2)"e"^((3pi)/4"i"`

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1: Complex Numbers - Exercise 1.3 [पृष्ठ १५]

APPEARS IN

संबंधित प्रश्‍न

Find the modulus and amplitude of the following complex numbers.

7 − 5i


Find the modulus and amplitude of the following complex numbers.

−8 + 15i


Find the modulus and amplitude of the following complex numbers.

−3(1 − i)


Find the modulus and amplitude of the following complex number.

−4 − 4i


Find the modulus and amplitude of the following complex numbers.

`sqrt(3) - "i"`


Find the modulus and amplitude of the following complex numbers.

`1 + "i"sqrt(3)`


Find the modulus and amplitude of the following complex numbers.

(1 + 2i)2 (1 − i)


Find real values of θ for which `((4 + 3"i" sintheta)/(1 - 2"i" sin theta))` is purely real.


If z = 3 + 5i then represent the `"z", bar("z"), - "z", bar(-"z")` in Argand's diagram


Express the following complex numbers in polar form and exponential form: 

`-1 + sqrt(3)"i"`


Express the following complex numbers in polar form and exponential form:

−1


Express the following numbers in the form x + iy: 

`sqrt(3)(cos  pi/6 + "i" sin  pi/6)`


Express the following numbers in the form x + iy:

`7(cos(-(5pi)/6) + "i" sin (- (5pi)/6))`


Express the following numbers in the form x + iy:

`"e"^((-4pi)/3"i")`


Find the modulus and argument of the complex number `(1 + 2"i")/(1 - 3"i")`


For z = 2 + 3i verify the following:

`bar((bar"z"))` = z


For z = 2 + 3i verify the following:

`("z" + bar"z")` is real


z1 = 1 + i, z2 = 2 − 3i. Verify the following : 

`bar("z"_1 + "z"_2) = bar("z"_1) + bar("z"_2)`


z1 = 1 + i, z2 = 2 − 3i. Verify the following : 

`bar("z"_1 - "z"_2) = bar("z"_1) - bar("z"_2)`


Select the correct answer from the given alternatives:

If arg(z) = θ, then arg `bar(("z"))` =


Select the correct answer from the given alternatives:

If z = x + iy and |z − zi| = 1 then


Answer the following:

Find the modulus and argument of a complex number and express it in the polar form.

8 + 15i


Answer the following:

Find the modulus and argument of a complex number and express it in the polar form.

6 − i


Answer the following:

Find the modulus and argument of a complex number and express it in the polar form.

`(-1 - "i")/sqrt(2)`


Answer the following:

Find the modulus and argument of a complex number and express it in the polar form.

− 3i


Answer the following:

Find the modulus and argument of a complex number and express it in the polar form.

`1/sqrt(2) + 1/sqrt(2)"i"`


Answer the following:

Represent 1 + 2i, 2 − i, −3 − 2i, −2 + 3i by points in Argand's diagram.


Answer the following:

Convert the complex numbers in polar form and also in exponential form.

z = `-6 + sqrt(2)"i"`


The modulus and amplitude of 4 + 3i are ______


If x + iy = `5/(3 + costheta + isintheta)`, then x2 + y2 is equal to ______ 


For all complex numbers z1, z2 satisfying |z1| = 12 and |z2 - 3 - 4i| = 5, the minimum value of |z1 - z2| is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×