Math, asked by sam63824, 11 months ago

2 x cube - 11 X square + 44 X + 27 if x is equal to 25 upon 3 - 4 iota​

Answers

Answered by Chamlagainikhil
0

Answer:

Step-by-step explanation:

Answered by ujalasingh385
1

Answer:

Answer is 2

Step-by-step explanation:

In this question,

f(x) = 2x^{3}\ -\ 11x^{2}\ +\ 44x\ +\ 27

We need to find f(x) when x  = \frac{25}{3-4i}

Therefore x = \frac{25\times (3+4i)}{(3-4i)\times (3+4i)}

                 x = \frac{25\times (3+4i)}{25}

                x = 3+4i

f(x) = 2x^{3}\ -\ 11x^{2}\ +\ 44x\ +\ 27

f(3+4i) = 2(3+4i)^{3}\ -\11(3+4i)^{2}\ +\44(3+4i)\ +\27

Therefore (3+4i)^{3}\ =\ (3)^{3}\ +\ (4i)^{3}\ +\ 3\times (3)^{2}\times 4i\ +\ 3\times 3\times (4i)^{2}

(3+4i)^{3}\ =\ 27\ +\ (-64i)\ +\ 108i\ -\ 144

(3+4i)^{3}\ =\ 44i\ -\ 117

2(3+4i)^{3}\ =\ 88i\ - 234

Similarly, (3+4i)^{2}\ =\ (3)^{2}\ +\ (4i)^{2}\ +\ 2\times 3\times 4i

(3+4i)^{2}\ =\ 9\ -\ 16\ +\ 24i

(3+4i)^{2}\ =\ -7\ +\ 24i

-11(3+4i)^{2}\ =\ 77\ -\ 264i

Now, 44(3+4i)\ =\ 132\ +\ 176i

Hence, f(3+4i) = 2(3+4i)^{3}\ -\11(3+4i)^{2}\ +\44(3+4i)\ +\27

            f(3+4i) = 88i - 234 + 77 -264i +132 +176i +27

            f(3+4i) = 2

Therefore f(3+4i) = 2

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