help please need quick repsone
\[\sqrt -36 \over 2+5i\]
rationalize the denominator
@phi @iGreen @Mashy @caitlinnr14 @ganeshie8
@amistre64
please show steps
what does it mean to rationalize something?
one sec let me think
getting all the 'radical' signs out of it
thats part of it sure. but in general, we want to convert something into a rational number. we have a complex number on the bottom that they want converted to a rational real number
oh
complex numbers are converted using a conjugate since: (a^2 - b^2) = (a+b)(a-b)
when b is a pure imaginary value like say 3i a^2 - (3i)^2 = a^2 -9i^2 but i^2 = -1 a^2 -9(-1) = a^2 + 9
is looks like the same principle from my last question
ok im starting to understand it
so, this gives us a similar formula: a^2 + b^2 = (a + bi) (a - bi)
so using a conjugate we end up with sqrt(-36) 2-5i -------- * ----- 2+5i 2-5i
so basicly you multiply out the complex terms conjate factors in the denominator to remove the imagery terms
yep
ok so that would be the answer
show me what your solution looks like
simplified or
simplified is fine ... ill know if you messed up :)
simplified it would be 30/29 + 12i / 29
29 is good now the top, lets chk sqrt(-36) = sqrt(36) sqrt(-1) = 6i 6i(2 - 5i) = 12i -30i^2 = 12i -30(-1) 30+12i ------- 29 :):)
yours is good
thx
yw :)
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