English

Find a and b if abi = 3a − b + 12i - Mathematics and Statistics

Advertisements
Advertisements

Question

Find a and b if abi = 3a − b + 12i

Sum

Solution

abi = 3a – b + 12i

0 + abi = (3a – b) + 12i

Equating real and imaginary parts, we get

3a – b = 0

∴ 3a = b   ...(i)

and ab = 12

∴ b = `12/"a"`   ...(ii)

Substituting b = `12/"a"` in (i), we get

3a = `12/"a"`

∴ 3a2 = 12

∴ a2 = 4

∴ a = ± 2

When a = 2, b = `12/"a" = 12/2` = 6

When a = – 2, b = `12/"a" = 12/(-2)` = – 6

∴ a = 2 and b = 6 or a = – 2 and b = – 6

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Complex Numbers - Exercise 1.1 [Page 6]

RELATED QUESTIONS

Express the given complex number in the form a + ib: i9 + i19


Express the given complex number in the form a + ib: i–39


Express the given complex number in the form a + ib: `(-2 - 1/3 i)^3`


Let z1 = 2 – i, z2 = –2 + i. Find Re`((z_1z_2)/barz_1)`


Evaluate the following:

\[i^{49} + i^{68} + i^{89} + i^{110}\]


Find the value of the following expression:

i5 + i10 + i15


Find the value of the following expression:

\[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}}\]


Express the following complex number in the standard form a + i b:

\[(1 + i)(1 + 2i)\]


Express the following complex number in the standard form a + i b:

\[\frac{2 + 3i}{4 + 5i}\]


Find the real value of x and y, if

\[(1 + i)(x + iy) = 2 - 5i\]


If \[\left( \frac{1 + i}{1 - i} \right)^3 - \left( \frac{1 - i}{1 + i} \right)^3 = x + iy\] find (xy).


Evaluate the following:

\[2 x^4 + 5 x^3 + 7 x^2 - x + 41, \text { when } x = - 2 - \sqrt{3}i\]


Write (i25)3 in polar form.


Express the following complex in the form r(cos θ + i sin θ):

 tan α − i


Write 1 − i in polar form.


Find the principal argument of \[\left( 1 + i\sqrt{3} \right)^2\] .


The value of \[(1 + i)(1 + i^2 )(1 + i^3 )(1 + i^4 )\] is.


If i2 = −1, then the sum i + i2 + i3 +... upto 1000 terms is equal to


If z is a non-zero complex number, then \[\left| \frac{\left| z \right|^2}{zz} \right|\] is equal to


\[(\sqrt{- 2})(\sqrt{- 3})\] is equal to


If \[z = \left( \frac{1 + i}{1 - i} \right)\] then z4 equals


If \[z = \frac{1}{1 - cos\theta - i sin\theta}\] then Re (z) =


If θ is the amplitude of \[\frac{a + ib}{a - ib}\] , than tan θ =


The argument of \[\frac{1 - i}{1 + i}\] is


\[\frac{1 + 2i + 3 i^2}{1 - 2i + 3 i^2}\] equals


A real value of x satisfies the equation  \[\frac{3 - 4ix}{3 + 4ix} = a - ib (a, b \in \mathbb{R}), if a^2 + b^2 =\]


Simplify : `sqrt(-16) + 3sqrt(-25) + sqrt(-36) - sqrt(-625)`


Simplify : `4sqrt(-4) + 5sqrt(-9) - 3sqrt(-16)`


Find a and b if (a+b) (2 + i) = b + 1 + (10 + 2a)i


Find a and b if `1/("a" + "ib")` = 3 – 2i


Express the following in the form of a + ib, a, b∈R i = `sqrt(−1)`. State the values of a and b:

`((2 + "i"))/((3 - "i")(1 + 2"i"))`


Express the following in the form of a + ib, a, b∈R i = `sqrt(−1)`. State the values of a and b:

(2 + 3i)(2 – 3i)


Evaluate the following : i35 


Evaluate the following : i888 


Evaluate the following : `1/"i"^58`


Evaluate the following : i–888 


Answer the following:

Show that z = `5/((1 - "i")(2 - "i")(3 - "i"))` is purely imaginary number.


State true or false for the following:

If a complex number coincides with its conjugate, then the number must lie on imaginary axis.


State True or False for the following:

The order relation is defined on the set of complex numbers.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×