With the information given, we deduce that the parabola is
Reflecting a function over the x axis means to change its sign. After the reflection, the parabola becomes
And to shift down a function, you subtract the shift from the equation: the equation becomes
Similarly, the other function is reflected over the x axis (sign change) and shifted up 3 (add 3 to the equation):
In order to compute the y intercept, we simply have to evaluate the functions at x=0: for the parabola we have
For the other function, we have