These points are also on the negative side of the x axis, at -pi/4 and -pi/2. When we move along the x axis, notice what happens to the y value. On the left side of zero, tangent is negative. At x=-pi/4, tangent=-1.
The Independent Online. David Cameron may have called a referendum on the EU to blackmail Europe, according to Vladimir Putin. The Russian president also questioned Mr Cameronâs decision to call the vote, as it has caused a âgreat problemâ.
Obama warns Russia of possible sectoral sanctions. Talks between U.S. President Barack Obama and German Chancellor Angela Merkel at the White House will focus on how the West should handle the growing conflict in Ukraine. Rough Cut (no reporter narration).