Verify the identity.? cos(α - β) - cos(α + β) = 2 sin α sin β
Show your work.
Show your work.
1 Answer
Mar 28, 2018
Explanation:
#"using the "color(blue)"trigonometric identities"#
#•color(white)(x)cos(x+-y)=cosxcosy∓sinxsiny#
#"cinsider the left side"#
#rArrcos(alpha-beta)=cosalphacosbeta+sinalphasinbeta#
#rArrcos(alpha+beta)=cosalphacosbeta-sinalphasinbeta#
#rArrcancel(cosalphacosbeta)+sinalphasinbetacancel(-cosalphacosbeta)+sinalphasinbeta#
#=2sinbetasinalpha=" right side "rArr"verified"#