Is y = 1/sqrt(x) a function? If so, what type of function it is?

How about y = | 1 - x^2 | ?

Alicense plate is to consist of 44 digits followed by 55 uppercase letters. determine the number of different license plates possible if the first and second digits must be? odd, and repetition is not permitted.

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Evaluate cos2θ for cosθ = square root of 3/2