Find the straight line equation that is tangent of the curve at the point (if any).
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
If one looks at this curve at x = 0 , the result is c o s ( 2 y ) = π . This is impossible for all real y since c o s ( 2 y ) ∈ [ − 1 , 1 ] . Therefore x = 0 is not contained anywhere on this curve and no tangents can be described there.