Monday, 6 June 2016

Find the complex square root of $7+6sqrt2i$


Find the complex square root of
$$7+6\sqrt2i$$
giving your answer in the form $x+iy$ where $x$ and $y$ are real.





The answer I have gotten is $-23+84\sqrt2i$
by squaring $7+6\sqrt2i$,
but the “correct” answer is $\pm(3+i\sqrt2)$.



Can you explain how I got this wrong?

No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...