Math, asked by reet232, 1 year ago

solve this plz........

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Answered by siddhartharao77
3
Given : (1/3 + 3i)^3

It is in the form of (a + b)^3 = a^3 + b^3 + 3a^2b + 3ab^2

= \ \textgreater \  ( \frac{1}{3} )^3 + (3i)^3 + 3( \frac{1}{3} )^2 (3i) + 3( \frac{1}{3})(3i)^2

We know that i^3 = -i, i^2 = -1

= \ \textgreater \   \frac{1}{27} - 27i + i - 9

= \ \textgreater \  ( \frac{1}{27} - 9) + i(-27 + 1)

= \ \textgreater \   \frac{-242}{27} - i26



Hope this helps!

siddhartharao77: :-)
reet232: thank u sooo much
siddhartharao77: ok
reet232: can u tell me what is (a+b) ^ 3 is???
siddhartharao77: it is a formula . (a + b)^3 = a^3 + b^3 + 3a^2b + 3ab^2.
reet232: is it really 3a^2b???
siddhartharao77: Actualy it can be written as a^3 + b^3 + 3ab(a + b).. Therefore a^3 + b^3 + 3ab * a + 3ab * b = a^3 + b^3 + 3a^2b + 3ab^2
reet232: okh....
reet232: thanks...
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