Prove that, cos10° cos20° +sin45° cos145° +sin55° cos245°=0
Prove that, cos10° cos20° +sin45° cos145° +sin55° cos245°=0 Solution: L.H.S =cos10° cos20° +sin45° cos145° +sin55° cos245° = $\frac{1}{2}$ ( 2cos10° …
Prove that, cos10° cos20° +sin45° cos145° +sin55° cos245°=0 Solution: L.H.S =cos10° cos20° +sin45° cos145° +sin55° cos245° = $\frac{1}{2}$ ( 2cos10° …