help me with the coce

Write a simple trig calculator script which gives the user the choice to calculate sin(x), cos(x) or tan(x) of an angle. Your script should:
 display the menu and read in the selection
 check if the selection is valid and if not display an error message
 use a switch...case statement to decide which calculation to do
 read in the angle and tell the user to enter the angle in degrees
 prevent errors such as trying to calculate the value of (tan 90o)
 display the result on screen.
Example menu :
Trig Function Calculator Program
1: sin(x)
2: cos(x)
3: tan(x)
0: exit program

Answer 1

[Image Analyst]

Start with this http://www.mathworks.com/matlabcentral/fileexchange/41440-simple-calculator and then build on it. Good luck.