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.
18 March: President Putin signs a bill to absorb Crimea into the Russian Federation. 17 March: The EU and US impose travel bans and asset freezes on several officials from Russia and Ukraine over the Crimea referendum.