Cartesian to Polar Coordinates 5

Question

Convert the Cartesian coordinate (5, 1) to polar coordinates, 

r =  

 =   

Answer 1

x=1 , y = 5

tanA = 5/1 = 5

A = about 78.7 degrees or 180+78.7 = 258.7 degrees but ignore the 2nd solution

A = 78.7 degrees as its the only solution in quadrant I

r^2 = 25+1 = 26

r = sqr26

polar coordinates are (sqr26, 78.7)