IIT JEE , AIEEE Forum - Mathematics , Algebra

nasa_hs

square root of complex no 5+12i is.......

3+2i 3-2i

+/-(3+2i) none

ans isc

A determinant IAI of order 3x3 is formed by usin d nos from d set {-1, 0, 1, 2}, d max value of d determinant is

27

-27

23

none

ans is 27

ultimator

= = =

I dunno whr i m wrong... i think abv is right n answer is none of these..... :(

ultimator

I think i found my mistake ..... oops !! split 12 into 2 and root -6 !!!
will try n post correct soln now......

ultimator

= ==

Rate me plz

spideyunlimited

1) z = 5 + 12 i
z = 13 (5/13 + 12/13 i)
z = 13 (cosQ + i.sinQ)
cosQ = 5/13 ; sinQ = 12/13

Using DeMoivre's theorem:
z^(1/2) = +- sqrt (13) * (cos(Q/2)+ i.sin(Q/2) )
z^(1/2) = +- sqrt (13) * [ rt ( (cosQ + 1)/2) + i.rt ( (1 - cosQ)/2) ]
z^(1/2) = +- sqrt (13) * [ rt (9/13) + i.rt ( 4/13) ]
z^(1/2) = +- sqrt (13) * [ 3/rt(13) + i.2/rt(13) ]
z^(1/2) = +- ( 3 + 2i)

yaswant

+-3+2i

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