# Why isn't my code working?

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Collin Kerr on 18 Apr 2016
Commented: James Tursa on 19 Apr 2016
%8 to 15 meters is the range
%Velocity is 0,15,30,45,60,75,90
clc,clear
F = input('Targeted Distance = ');
V_o = input('Velocity at launch = ');
S_o = input('Elevation angle at launch = ');
a=9.81; %Its a given
b=V_o*sind(S_o) %It makes the coding a bit less confusing.
c=0; %Also a given
fprintf('The targeted distance for the launch is %d meters. \n', F)
fprintf('The velocity for the launch is %d meters per second. \n', V_o)
fprintf('The elevation angle for the launch is %d degrees. \n', S_o)
Q1=(-b-sqrt(b^2-4*a*c))/2*a;
disp(Q1)
##### 2 CommentsShowHide 1 older comment
James Tursa on 19 Apr 2016
Duplicate Question.

James Tursa on 19 Apr 2016
You need to enclose the denominator in parentheses:
Q1=(-b-sqrt(b^2-4*a*c))/(2*a);
The way you have it coded, since / and * have the same precedence the operations are performed left to right and MATLAB sees your current coded expression as:
Q1=((-b-sqrt(b^2-4*a*c))/2) * a;
Which is not what you wanted.