Step-by-step explanation:
1. Sine and Cosine are never greater than 1 because they are the ratio of the leg of a right triangle to the hypotenuse. The hypotenuse is never shorter than one of the legs of a right triangle, so the ratio is at most 1.
__
2. Secant and cosecant are the reciprocals of the cosine and sine (respectively), so are the reciprocals of numbers that are at most 1. Therefore, they can never be less than 1 (in magnitude).
__
3. Tangent and cotangent (and secant and cosecant) are sometimes undefined because they are the ratios of triangle side lengths. The side length used in the denominator may be zero, causing the ratio to be undefined.