diketahui cos (x-y)=3/4 dan sinx.siny=3/10 nilai tan x. tan y =

cos(x-y) = 3/4
cosx.cosy + sinx.siny = 3/4
cosx.cosy = 3/4 - sinx.siny
=3/4 - 3/10
= 15/20 - 6/20
= 9/20

tanx.tany = (sinx.siny)/(cosx.cosy)
= (3/10) / (9/20)
= 3/10 × 20/9
= 2/3

smga membantu