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б) <span>p³-p²-4p+4=0,
p</span></span>²<span><span>(p-1)-4(p-1)=0,
(p-1)(p</span></span>²-4)=0,
<span><span>p-1=0 или p</span></span>²-4=0
<span><span>p=1 или </span></span>
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4cos²x+4sinx-1=0
4(1-sin²x) +4sinx-1=0
4-4sin²x+4sinx-1=0
4sin²x-4sinx-3=0
Пусть sinx=t (|t|≤1)
4t²-4t-3=0
D=16+48=64; √D=8
x1=(4+8) /8=1.5
x2=(4-8) /8=-1/2
x1=1.5- не удовлетворяет при |t|≤1
замена
sinx=-1/2
x=(-1)^(k+1) *π/6+πk, k € Z