Let's examine the following graphs: Again, the period of the original sine curve has changed here, as we would expect. The difference with a negative value of b however, is our sine curves have the same period as the positive values of b above, but now they are reflected across the x-axis. For a direct comparison between positive and negative values of b, click here.
Quick Answer. As of 2014, Joachim Gauck is the president of Germany. The 72-year-old was elected to the position on March 18, 2012, in Berlin after receiving 991 of the 1,228 valid votes.
Barack Obama, Democrat, (born August 4, 1961 in Honolulu,  Hawaii) officially became the forty-fourth President of the United  States, on January 20, 2009 and was re-electe â¦ d for a second term on  November 6, 2012. Barack Obama became president of the United States of America in  2009 and is the current president. Before he became president there  was George W. Bush and Bill Clinton.