Question

Which trigonometric functions do not have real zeros?

sine, cosine, tangent, cosecant, secant, or cotangent.

Answer 1

http://img.sparknotes.com/figures/A/ad79275cb59e569b790cb945a4ffc553/triggraphs.gif

take a peek, which ones DO NOT touch the x-axis?

Answer 2

sine and cosine?

Answer 3

@jdoe0001 or no , cosecant and secant?

Answer 4

yes, those 2 guys, do not touch the x-axis, and thus have no so-called real-zeros or roots :)

Answer 5

Okay, thank you so much! What would it mean if the question becomes which ones are even?

Answer 6

http://www.mathsisfun.com/algebra/functions-odd-even.html

Answer 7

Thanks again! (:

Answer 8

yw