Warning: jsMath requires JavaScript to process the mathematics on this page.
If your browser supports JavaScript, be sure it is enabled.

Solution 4.3:4c

The formula for double angles gives

\displaystyle \sin 2v=2\sin v\cos v

and from exercise b, we have \displaystyle \sin v = \sqrt{1-b^2}\,. Thus,

\displaystyle \sin 2v = 2b\sqrt{1-b^2}\,\textrm{.}