what is frequency of the function f(x) ?
F(x) = -sin (3x) -1
enter your answer in simplest fraction form
By frequency, I think you mean period. The period of a sine function is 2pi/(whatever number is in the brackets of the sine).
So, for this question, the period (or frequency) is 2pi/3.
I know it is harder but try to teach without giving final answer whenever it is possible. (most of the time anyway)
Encourage the kids to tell you what they think that the answer is.
If they do not get back to you them maybe they were only ever interested in the answer (which we do not want to encourage).
Or maybe they have been given all that they need.