मराठी

If a = cosθ + isinθ, find the value of aa1+a1-a.

Advertisements
Advertisements

प्रश्न

If a = cosθ + isinθ, find the value of `(1 + "a")/(1 - "a")`.

बेरीज
Advertisements

उत्तर

Given that: a = cosθ + isinθ

∴ `(1 + a)/(1 - a) = (1 + cos theta + i sin theta)/(1 - cos theta - i sin theta)`

= `(1 + cos theta + i sin theta)/(1 - cos theta - i sin theta) xx (1 - cos theta + i sin theta)/(1 - cos theta + i sin theta)`

= `(1 - cos theta + i sin theta + cos theta - cos^2 theta + i sin theta cos theta + i sin theta - i sin theta cos theta + i^2 sin^2 theta)/((1 - cos theta)^2 - i^2 sin^2 theta)`

= `(1 + i sin theta - cos^2 theta + i sin theta - sin^2 theta)/(1 + cos^2 theta - 2 cos theta + sin^2 theta)`

= `(sin^2 theta + 2i sin theta - sin^2 theta)/(1 + 1 - 2 cos theta)`

= `(2i sin theta)/(2 - 2 cos theta)`

= `(2i sin theta)/(2(1 - cos theta))`

= `(i sin theta)/(1 - cos theta)`

= `(2 sin  theta/2 cos  theta/2.i)/(2sin^2  theta/2)`

= `cot  theta/2 . i`

Hence, `(1 + a)/(1 - a) = icot  theta/2`.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 5: Complex Numbers and Quadratic Equations - Exercise [पृष्ठ ९१]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
पाठ 5 Complex Numbers and Quadratic Equations
Exercise | Q 6 | पृष्ठ ९१

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Express the given complex number in the form a + ib: (1 – i) – (–1 + i6)


Express the given complex number in the form a + ib: (1 – i)4


Evaluate: `[i^18 + (1/i)^25]^3`


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


Let z1 = 2 – i, z2 = –2 + i. Find `"Im"(1/(z_1barz_1))`


Evaluate the following:

i457


Evaluate the following:

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


Find the value of the following expression:

i49 + i68 + i89 + i110


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

\[\frac{1 - i}{1 + i}\]


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

\[(1 + 2i )^{- 3}\]


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

\[\frac{3 - 4i}{(4 - 2i)(1 + i)}\]


Find the real value of x and y, if

\[(3x - 2iy)(2 + i )^2 = 10(1 + i)\]


Find the real value of x and y, if

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


Find the multiplicative inverse of the following complex number:

\[(1 + i\sqrt{3} )^2\]


Find the smallest positive integer value of m for which \[\frac{(1 + i )^n}{(1 - i )^{n - 2}}\] is a real number.

 

Evaluate the following:

\[x^4 - 4 x^3 + 4 x^2 + 8x + 44,\text {  when } x = 3 + 2i\]


Evaluate the following:

\[x^6 + x^4 + x^2 + 1, \text { when }x = \frac{1 + i}{\sqrt{2}}\]


Write the argument of −i.


Write the value of \[\sqrt{- 25} \times \sqrt{- 9}\].


Write the sum of the series \[i + i^2 + i^3 + . . . .\] upto 1000 terms.


If \[\left| z + 4 \right| \leq 3\], then find the greatest and least values of \[\left| z + 1 \right|\].


If a = cos θ + i sin θ, then \[\frac{1 + a}{1 - a} =\]


The principal value of the amplitude of (1 + i) is


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


The value of (i5 + i6 + i7 + i8 + i9) / (1 + i) is


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


The complex number z which satisfies the condition \[\left| \frac{i + z}{i - z} \right| = 1\] lies on


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


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

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


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

(1 + i)−3 


Evaluate the following : i888 


Evaluate the following : i93  


Evaluate the following : i403 


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


If z1 = 3 – 2i and z2 = –1 + 3i, then Im(z1z2) = ______.


If z1 and z2 both satisfy `z + barz = 2|z - 1|` arg`(z_1 - z_2) = pi/4`, then find `"Im" (z_1 + z_2)`.


Match the statements of column A and B.

Column A Column B
(a) The value of 1 + i2 + i4 + i6 + ... i20 is (i) purely imaginary complex number
(b) The value of `i^(-1097)` is (ii) purely real complex number
(c) Conjugate of 1 + i lies in (iii) second quadrant
(d) `(1 + 2i)/(1 - i)` lies in (iv) Fourth quadrant
(e) If a, b, c ∈ R and b2 – 4ac < 0, then
the roots of the equation ax2 + bx + c = 0
are non real (complex) and
(v) may not occur in conjugate pairs
(f) If a, b, c ∈ R and b2 – 4ac > 0, and
b2 – 4ac is a perfect square, then the
roots of the equation ax2 + bx + c = 0
(vi) may occur in conjugate pairs

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×