What is the square root of 9/16, 9 to the power of two

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

Standard deviation of 19,29,21,22,23