Question #10263
1 Answer
Dec 14, 2017
Explanation:
#"using the "color(blue)"difference to product formula"#
#color(red)(bar(ul(|color(white)(2/2)color(black)(cosC-cosD=-2sin((C+D)/2)sin((C-D)/2))color(white)(2/2)|)))#
#"here "C=x+pi/6" and "D=x-pi/6#
#rArrcos(x+pi/6)-cos(x-pi/6)#
#=-2sin((x+pi/6+x-pi/6)/2)sin((x+pi/6-x+pi/6)/2)#
#=-2sinxsin(pi/6)#