I am attempting to understand how I can derive a new expression as a function of another variable in this existing expression. This is a college undergraduate course but I can't recall doing this much before, maybe in high school. I have taken all the way up to ODE's and PDE's. The confusion that begins to arise is when attempting to manipulate this expression due to its trigonometric function. With that being said, if one has an equation such that: B(r) = Bsin(A f r + θ) How can one solve to express this as a function of lets say f? Any insight towards mathematical properties would be greatly appreciated!