Q8 of 48 Page 86

Prove the following:

sin 35° sin 55° – cos 35° cos 55° = 0

Taking L.H.S we get,


sin (90˚ – 55˚).sin(90˚ – 35˚) – cos 35˚.cos 55˚


⇒ cos 55˚.cos 35˚ – cos 35˚.cos 55˚


⇒ cos 35˚.cos 55˚ – cos 35˚.cos 55˚


= 0.


=R.H.S


Hence, proved.


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