5. 20 pts: (a) Create a variable named theta_d. Assign an angle of 60 degrees to it. Prove the trigonometric identity sin20+ cos20 = 1 Here the 8 is the variable 'theta_d' you created. (b) Convert the theta_d into radians and store in a new variable theta_r and then repeat (a) to prove the trigonometric identity again. (don't use function deg2rad).