1. Sketch the curve \(y = \sqrt{1 - x} + \sqrt{3 + x}\). Use your sketch to show that only one real value of \(x\) satisfies \[\sqrt{1 - x} + \sqrt{3 + x} = x + 1,\] and give this value.

For what values of \(x\) is \(y\) defined?

Try evaluating the function \(y = f(x)\) for some integer values of \(x\). What does this suggest about the function?

Are there any stationary points? If so, where and of what type?