Đáp án:
`min_C=3/4<=>x=1.`
Giải thích các bước giải:
`C=(x+sqrtx+1)/(sqrtx+1)^2(x>=0)`
`C=(x+sqrtx+1)/(x+2sqrtx+1)`
Xét `4C-3`
`4C-3=(4x+4sqrtx+4-3x-6sqrtx-3)/(x+2sqrtx+1)`
`4C-3=(x-2sqrtx+1)/(x+2sqrtx+1)`
`4C-3=(sqrtx-1)^2/(sqrtx+1)^2>=0`
`=>4C-3>=0`
`=>4C>=3`
`=>C>=3/4`
Dấu "=" xảy ra khi `sqrtx=1<=>x=1`
Vậy `min_C=3/4<=>x=1.`
C=$\frac{x+\sqrt[]{x}+1}{(\sqrt[]{x}+1)^2}$
C=$\frac{x+\sqrt[]{x}+1}{(x+2\sqrt[]{x}+1}$
<=> C(x+2\sqrt[]{x}+1)=\sqrt[]{x} +x+1
<=> xC+2\sqrt[]{x}C+C-x-\sqrt[]{x}-1=0
<=> x(C-1)+\sqrt[]{x}(2C-1)+C-1=0
Δ= 4C²-4C+1-4C²+8C-4
Δ=4C-3≥0
<=> 4C≥3
<=> C≥3/4
=> C min =3/4
thay 3/4 vào PT tìm x
ta đc x=1
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giải giúp mình với mình đang cần gấp
Calli: Makima YC: ng tl phải là con trai (chỉ thế thôi), không app ra giấy NL: ai đọc bộ thợ săn quỷ chx, hóng :>>
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Vẽ con khỉ đang ăn trái chuối = ))
mn oi giup mk vs gap qua mk con 30 phut ak
a)16x^3y+1/4yz^3 b)x^4-x^2+2x-1 c)x^4+2x^3-6x-9=0 gIÚP MÌNH NGAY VỚI Ạ
giúp e gấp với ạ, em cảm ơn mng nhiều
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phân số -3 phần 7 có phân số nghịch đảo là
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