<span>64y2−7y+k = (8у-к)^2
2*8у*к=7у
2*8*к=7
16к=7
к=7/16
к=0,4375
</span>64y2−7y+(0,4375)^2 = <span>64y2−7y+0,19140625</span>
Tg(a+b)=(tga+tgb)/1-tga*tgb)=(1/5+2/3)/(1-1/5*2/3)=1 ctg(a-b)= (1+3/2*5/2)/(3/2-5/2)=-4,75 tg(π/4+a)=(tgπ/4+tga)/(1-tgπ/4*tga)=(1+tga)/(1-tga) =(1+12/13*13/5)/(1-12/5) =17/7