I am trying to create a function for finding out the positive root for a quadratic equation. I have written the following code for the same but I keep getting an error stating that b not found and the following appears:
Positive_Root < function(x,y,z){

x < a

y < b

z < c

b+sqrt(b^24*a*c)/2*a
 }
Positive_Root(2,1,4)
Error in Positive_Root(2, 1, 4) : object 'b' not found