Claudia Fragapane. Claudia Fragapane (born 24 October 1997 in Bristol) is a British artistic gymnast. She came to prominence at the 2014 Commonwealth Games, where she was the first English woman to win four gold medals since 1930.
The unit circle definition is tan(theta)=y/x or tan(theta)=sin(theta)/cos(theta). The tangent function is negative whenever sine or cosine, but not both, are negative: the second and fourth quadrants. Tangent is also equal to the slope of the terminal side. tangent right triangle trigonometry the unit circle.
From the geometry of the spherical mirror, note that the focal length is half the radius of curvature: As in the case of lenses, the cartesian sign convention is used here, and that is the origin of the negative sign above. The radius r for a concave mirror is a negative quantity (going left from the surface), and this gives a positive focal length, implying convergence.