मराठी

Find the value of: 2x3 – 11x2 + 44x + 27, if x = 253-4i

Advertisements
Advertisements

प्रश्न

Find the value of: 2x3 – 11x2 + 44x + 27, if x = `25/(3 - 4"i")`

बेरीज
Advertisements

उत्तर

x = `25/(3 - 4"i")`

∴ x = `(25(3 + 4"i"))/((3 - 4"i")(3 + 4"i")`

= `(25(3 + 4"i"))/(9 - 16"i"^2)`

= `(25(3 + 4"i"))/(9 - 16(-1))`                 ...[∵ i2 = – 1]

= `(25(3 + 4"i"))/25`

∴ x = 3 + 4
∴ x – 3 = 4i
∴ (x –  3)2 = 16i2
∴ x2 –  6x + 9 = 16(–  1)      ...[∵ i2 = – 1]
∴ x2 – 6x + 25 = 0

                      2x + 1
`x^2 – 6x + 25")"overline(2x^3 - 11x^2 + 44x + 27)"`
                      2x3 – 12x2 + 50x
                    –      +         –                      
                                   x2 – 6x + 27
                                  x2 – 6x + 25
                              –      +      –                
                                                  2

∴ 2x3 – 11x2 + 44x + 27
= (x2 – 6x + 25) (2x + 1) + 2
= 0.(2x + 1) + 2            ...[From (i)]
= 0 + 2
= 2

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Complex Numbers - EXERCISE 3.1 [पृष्ठ ३८]

APPEARS IN

संबंधित प्रश्‍न

Find the value of i + i2 + i3 + i4 


Simplify:

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


Find the value of 1 + i2 + i4 + i6 + i8 + ... + i20


Show that 1 + i10 + i100 − i1000 = 0 


Is (1 + i14 + i18 + i22) a real number? Justify your answer


If (a + ib) = `(1 + "i")/(1 - "i")`, then prove that (a2 + b2) = 1


Answer the following:

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

(2i3)2 


Answer the following:

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

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


Answer the following:

Solve the following equations for x, y ∈ R:

(x + iy) (5 + 6i) = 2 + 3i


Solve the following equation for x, y ∈ R:

2x + i9y (2 + i) = xi7 + 10i16


Answer the following:

Evaluate: i131 + i49 


Answer the following:

Find the value of x3 + 2x2 − 3x + 21, if x = 1 + 2i


If |z + 1| = z + 2(1 + i), then find z.


Find the complex number satisfying the equation `z + sqrt(2) |(z + 1)| + i` = 0.


If z1 and z2 are complex numbers such that z1 + z2 is a real number, then z2 = ______.


Which of the following is correct for any two complex numbers z1 and z2?


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


If α, β, γ and a, b, c are complex numbers such that `α/a +  β/b + γ/c` = 1 + i and `a/α +  b/β + c/γ` = 0, then the value of `α^2/a^2 +  β^2/b^2 + γ^2/c^2` is equal to ______.


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)`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×