<OAC = (180-140)/2=20 градусов
<OAC = <OCA = 20градусов
<A = 2*<OAC
<A = 2*20= 40 градусов
<A = <C = 40градусов
<B = 180-(40*2)=100 градусов
Y ' - y*ctgx = 0
y' = dy/dx ==>
dy/dx = y*ctgx
dy/y = ctgx*dx
∫ dy/y = <span>∫ ctgx*dx
</span>ln y = ln (sinx)
y = sinx + C
а). 1/2*√5=1*√5/2√5*√5=√5/2*5=√5/10
б). 8/√7-1=8(√7-1)/(√7-1)(√7+1)=8(√7-1)/7-1=8(√7-1)/6=4√7-4/3
(7х-3)в кводрате= 49x квадрат -42х+9