CBSE Class 11-science Answered

the roots of -18i

Asked by simrangurdasani05 | 17 Jul, 2022, 03:39: AM

Expert Answer

Let -18i = a + ib

L e t space square root of negative 18 i end root equals a plus i b rightwards double arrow negative 18 i equals a squared minus b squared plus 2 i a b C o m p a r i n g space r e a l space a n d space i m a g i n a r y space t e r m s space w e space g e t a squared minus b squared equals 0 space space a n d space 2 a b equals negative 18 space rightwards double arrow space b equals negative 9 over a rightwards double arrow a squared minus 81 over a squared equals 0 rightwards double arrow left parenthesis a squared minus 9 right parenthesis left parenthesis a squared plus 9 right parenthesis equals 0 rightwards double arrow a squared equals 9 rightwards double arrow a equals plus-or-minus 3 W h e n space a equals 3 space w e space g e t space b equals negative 3 W h e n space a equals negative 3 space w e space g e t space b equals 3 H e n c e comma space square root of negative 18 i end root equals plus-or-minus left parenthesis 3 plus 3 i right parenthesis

Answered by Renu Varma | 17 Jul, 2022, 09:40: PM

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