M Mrspi Senior Member Joined Dec 17, 2005 Messages 2,116 Oct 26, 2009 #2 itzel616@yahoo.com said: sin4cos5 + cos4sin5 =sin(4+5) =9 Click to expand... No, not quite. sin A cos B + cos A sin B = sin (A + B) sin 4 cos 5 + cos 4 sin 5 = sin (4 + 5) sin (4 + 5) = sin 9................NOT 9
itzel616@yahoo.com said: sin4cos5 + cos4sin5 =sin(4+5) =9 Click to expand... No, not quite. sin A cos B + cos A sin B = sin (A + B) sin 4 cos 5 + cos 4 sin 5 = sin (4 + 5) sin (4 + 5) = sin 9................NOT 9