How do you simplify sin(u-v)cosv+cos(u-v)sinvsin(u−v)cosv+cos(u−v)sinv?
1 Answer
Jun 5, 2018
Explanation:
"using the "color(blue)"addition formulae"using the addition formulae
•color(white)(x)sin(x+-y)=sinxcosy+-cosxsiny∙xsin(x±y)=sinxcosy±cosxsiny
•color(white)(x)cos(x+-y)=cosxcosy∓sinxsiny∙xcos(x±y)=cosxcosy∓sinxsiny
•color(white)(x)sin^2x+cos^2x=1∙xsin2x+cos2x=1
sin(u-v)cosvlarrcolor(red)"first term"sin(u−v)cosv←first term
=(sinucosv-cosusinv)cosv=(sinucosv−cosusinv)cosv
=sinucos^2vcancel(-cosucosvsinv)
cos(u-v)sinvlarrcolor(red)"second term"
=(cosucosv+sinusinv)sinv
=cancel(cosucosvsinv)+sinusin^2v
"adding the 2 expansions gives"
sinucos^2v+sinusin^2v
=sinu(cos^2v+sin^2v)=sinu