4*4=16(cм) - вторая сторона
Р=(a+b)*2
(16+4)*2=20*2=40(cм) - периметр
S=ab
16*4=64(см²)-площадь
400:b-32=48
400:b=48+32
400:b=80
b=400/80
b=5
Проверка: 400:5-32=48
48=48
Tgˇ2x=(1-cosx)/(1-sinx)
sinˇ2x/cosˇ2x = (1-cosx)/(1-sinx)
sinˇx/(1-sinˇ2x)=(1-cosx)/(1-sinx)
sinˇ2x=(1-cosx)(1+sinx)(1-sinx)/(1-sinx)
sinˇ2x = (1-cosx)(1+sinx)
1-cosˇ2x = (1-cosx)(1+sinx)
(1+cosx)(1-cosx)=(1-cosx)(1+sinx)
1+cosx=1+sinx
cosx=sinx
a)x=pí/4+2k.pí
b)x=5pí/4+2k.pí
k=0,1,-1,2,-2,.......
∠ABC = 180°
∠ABK - x
∠KBC - x+34
∠ABC=∠ABK + ∠KBC
180° = x + x + 34° = 2x + 34°
2x = 180° - 34° = 146°
x = 73° - ∠ABK
∠KBC = 73° + 34° = 107°
(<span>х- 1 2/3) + 2 5/6 = 3 7/15
(х-5/3)+17/6=52/15
х-5/3+17/6=52/15
х+7/6=52/15
ъ=52/15-7/6
х=23/10=2,3</span>