The unreal world -'3'

Evaluate; i 37 + 1 i 67 { i }^{ 37 }+\frac { 1 }{ { i }^{ 67 } }

0 2i i -i

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3 solutions

i 37 = i ( 4 × 9 ) × i = ( i 4 ) 9 × i = ( 1 × i ) = i . 1 i 67 = 1 i 67 × i i = i i 68 = i ( i 4 ) 17 = i 1 = i . ( i 37 + 1 i 67 ) = ( i + i ) = 2 i . { i }^{ 37 }={ \quad i }^{ \left( 4\times 9 \right) }\times i\quad =\quad \left( { i }^{ 4 } \right) ^{ 9 }\times i\quad =\quad \left( 1\times i \right) \quad =\quad i.\\ \frac { 1 }{ { i }^{ 67 } } \quad =\quad \frac { 1 }{ { i }^{ 67 } } \times \frac { i }{ i } \quad =\quad \frac { i }{ { i }^{ 68 } } \quad =\quad \frac { i }{ { \left( { i }^{ 4 } \right) }^{ 17 } } \quad =\quad \frac { i }{ 1 } \quad =\quad i.\\ \therefore \quad \left( { i }^{ 37 }+\frac { 1 }{ { i }^{ 67 } } \right) \quad =\quad \left( i+i \right) =\quad 2i.

37 1 ( m o d 4 ) , 67 1 ( m o d 4 ) i 37 = i 1 , 1 i 67 = i 67 = i 1 . E x p . = 2 i . 37 \equiv 1 \pmod {4}, ~~-67 \equiv 1 \pmod {4} \\\therefore ~i^{37}=i^1 ,~~\dfrac 1 {i^{67}}=i^{-67}=i^1. ~~\implies Exp.= 2i. \\~~\\

Dinesh Nath Goswami has nicely solved the problem. I give here only to show the mod. way. I have up voted for him.

Ramiel To-ong
Jun 8, 2015

nice approach

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