1.cos−1(45)+cos−1(1213)=\cos^{-1}\left(\frac{4}{5}\right)+\cos^{-1}\left(\frac{12}{13}\right)=cos−1(54)+cos−1(1312)=a.cos−1(2425)\cos^{-1} \left( \frac{24}{25} \right)cos−1(2524)b.cos−1(3365)\cos^{-1} \left( \frac{33}{65} \right)cos−1(6533)c.cos−1(513)\cos^{-1} \left( \frac{5}{13} \right)cos−1(135)d.cos−1(35)\cos^{-1} \left( \frac{3}{5} \right)cos−1(53)Login to continueOnly logged in users canattempt or see the solution.
