the letter C, in caps "C" appears in the lower right side of the screen on my HP15C handheld calculator [10 series]The sin,cos,&tan functions are not giving correct answers and I just changed the battrys; I do not have an owners manual; how do I rid myself of this mode or what/why is it doing this? I loaned it to a friend to do calc's during class, he has no clue what he did...I donot know how to reset...or if that helps this problem?? please help; 3/30/08pocoranch@sbcglobal.net
Tags: