Answer:
5√5
Step-by-step explanation:
Simplify the radical by breaking the radicand up into a product of known factors, assuming positive real numbers.
5√5



so if you notice yours

now.. normally the function

has a D value of 0, or no vertical shift, and the amplitude and the period simply make the wave taller and thinner, but the midline is still the x-axis
now, with D = 6.1, that moves the midline up vertically that much
now.. the period, well, B = 5/3, normal period of cosine is

so, the new period will be

notice the picture below
the vertical shift by the D component, or 6.1, moved the midline to y = 6.1 :)
The value for c is A. 49. That comes from the process of completing the square where you take half the linear term, square it, and add it in. Our linear term is 14. Half of 14 is 7, and 7 squared is 49. So A