Question

зная что cos a=12/13,3п/2 найдите tg(п/4+a)

Answer 1

sina=√(1-cos²a)=√(1-144/169)=√(25/169)=5/13
tga=sina/cosa=5/13:12/13=5/13*13/12=5/12
tg(π/4+a)=(tga+tgπ/4)/(1-tga*tgπ/4)=(5/12+1):(1-5/12*1)=17/12:7/12=17/12*12/7=
=17/7