Question #3acab
1 Answer
May 14, 2017
Explanation:
#"using right triangle with a vertex at the origin and angle " #
#theta," with sides corresponding to " theta#
#"adjacent "=x ," opposite " =y ," hypotenuse " =r#
#rArrsintheta=y/r , costheta=x/r" and " r^2=x^2+y^2#
#rArr1-sin^2theta=1-y^2/(r^2)=r^2/(r^2)-y^2/(r^2)#
#rArr1-sin^2theta=(r^2-y^2)/r^2=x^2/(r^2)=cos^2theta#
