Is there a mistake with my code to calculate ballistic trajectory?

function [x,y]= DeLaPena_Trajectory(velocity,angle)
%Fucntion that calculates x and y position of ball
%Inputs: Velocity(m/s) and Angle(degrees)
%Outputs: [x,y]



narginchk(2,2)
 
%Check for valid inputs
if velocity<0
    error('Velocity must be a positive number')
end 

if angle<0
    error('Angle must be positive')
end 

%Defines the velocities
v_x= velocity*cosd(angle); %x-component of v
v_y= velocity*sind(angle); %y-component of v

%Define the displacement equations and time equations 

t= (2*v_y)/9.81; %time of ballistic

x= v_x*t; %x-location

y= v_y*t-(1/2)*9.81*t^2; %y-location

This is my user-defined function for ballistic trajectory is there anything wrong with my code, I dont get the same answers as I would when I do it by hand.

[per isakson]

See Projectile Motion Calculator

Answer 1

[Hiro Yoshino]

Following the equation of motion

The time the ball reaches the highest point is given by

Yours looks ok though it depends what you want to get from the code...