Learner
secant and cosecant functions have no values in (-1, 1)
So square of these can't have values in [0, 1)
Thus range of both sec²x and csc²x lies in [1, ∞)
tan and cot functions both have range in (-∞, ∞)
So range of the squared functions, tan²x and cot²x lies in [0, ∞)