tinh gia tri nho nhat x^2-10x+26
1.gia tri nho nhat cua x^2-x+1
2. gia tri nho nhat cua x^2+10x+2041
Bài 1:
\(x^2-x+1=x^2-x+\frac{1}{4}+\frac{3}{4}\)
\(=\left(x^2-x+\frac{1}{4}\right)+\frac{3}{4}\)
\(=\left(x-\frac{1}{2}\right)^2+\frac{3}{4}\ge\frac{3}{4}\)
Dấu "=" khi \(x=\frac{1}{2}\)
Vậy \(Min=\frac{3}{4}\) khi \(x=\frac{1}{2}\)
Bài 2:
\(x^2+10x+2041=x^2+10x+25+2016\)
\(=\left(x^2+10x+25\right)+2016\)
\(=\left(x+5\right)^2+2016\ge2016\)
Dấu "=" khi \(x=-5\)
Vậy \(Min=2016\) khi \(x=-5\)
tinh gia tri nho nhat D=x+2√(x-2)+16
\(D=x+2\sqrt{x-2}+16\)
ĐK: \(x\ge2\)
\(D=x-2+2\sqrt{x-2}+1+17\)
\(D=\left(\sqrt{x-2}+1\right)^2+17\ge1+17=18\)
Vậy Min D = 18 <=> x=2
gia tri lon nhat va nho nhat cua ham so y=x 4-4x3-x2+10x-3 tren doan [1;4]
xet tinh dong bien, nghich bien va tinh gia tri lon nhat, gia tri nho nhat cua ham so:
a) y = x mu2 ten doan (-3;0)
P=|x^2-x+1|+|x^2-x-2|
Tinh gia tri nho nhat cua P
x^2-x+1+x^2-x-2=2x^2-2x+1=1-2x+x^2 + x^2= (1-x)^2 + x^2
Ta có (1-x)^2 +x^2>=x^2
Khi 1-x=0 <=> x=1
Vậy GTNN là 1 khi 1-x=0 <=> x=1
C=-(x+2)^2-(2x+y+1)^2+2016
Tinh gia tri lon nhat hoac nho nhat
tinh gia tri nho nhat cua cac bieu thuc sau: Q=9/2+|2/5-x|
x2-2x+5
=x2-2x+1+4
=(x-1)2+4
Vì:
Min = 4 khi x=1
Tinh gia tri h(x) voi x de da thuc :
\(\left(X+\dfrac{1}{2}\right)^2+1\)
Dat gia tri nho nhat
Ta có:
\(\left(x+\dfrac{1}{2}\right)^2\)+1\(\ge\)1
mà \(\left(x+\dfrac{1}{2}\right)^2\)\(\ge\)0
Dấu ''='' xảy ra khi:
\(\left(x+\dfrac{1}{2}\right)^2\)=0
=>x+\(\dfrac{1}{2}\)=0
=>x=\(\dfrac{-1}{2}\)
Vậy GTNN của \(\left(x+\dfrac{1}{2}\right)^2\)+1 là 1 khi x=\(\dfrac{-1}{2}\)
tinh gia tri nho nhat√(x+√x+81)-10
ý bạn là \(\sqrt{\left(x+\sqrt{x+81}\right)}-10\) á