Tính:
\(\sqrt{17-\sqrt{33}}\cdot\sqrt{17+\sqrt{33}}\)
Tính \(\sqrt{17-\sqrt{33}}.\sqrt{17+\sqrt{33}}\) có kết quả là
\(\sqrt{17-\sqrt{33}}\cdot\sqrt{17+\sqrt{33}}\)
\(=\sqrt{17^2-\left(\sqrt{33}\right)^2}\)
\(=\sqrt{289-33}=\sqrt{256}=16\)
\(\sqrt{17-\sqrt{33}}.\sqrt{17+\sqrt{33}}\)
\(\sqrt{17-\sqrt{33}}\sqrt{17+\sqrt{33}}=\sqrt{\left(17-\sqrt{33}\right)\left(17+\sqrt{33}\right)}\)
\(=\sqrt{17^2-33}=\sqrt{256}=16\)
\(\sqrt{42-10\sqrt{17}\:}+\sqrt{33-8\sqrt{17}}\)
Giải:
\(\sqrt{42-10\sqrt{17}}+\sqrt{33-8\sqrt{17}}\)
\(=\sqrt{\left(5-\sqrt{17}\right)^2}+\sqrt{\left(4-\sqrt{17}\right)^2}\)
\(=\left|5-\sqrt{17}\right|+\left|4-\sqrt{17}\right|\)
\(=5-\sqrt{17}+\sqrt{17}-4\)
\(=1\)
Vậy ...
\(\sqrt{42-10\sqrt{17}}+\sqrt{33-8\sqrt{17}}=\sqrt{25-2.5.\sqrt{17}+17}+\sqrt{16-2.4.\sqrt{17}+17}=\sqrt{\left(5-\sqrt{17}\right)^2}+\sqrt{\left(4-\sqrt{17}\right)^2}=\left|5-\sqrt{17}\right|+\left|4-\sqrt{17}\right|=5-\sqrt{17}+\sqrt{17}-4=1\)
1) so sánh
a) \(\sqrt{33}-\sqrt{17}\) và \(6-\sqrt{15}\)
b) \(4\sqrt{5}\) và \(5\sqrt{3}\)
c) \(\sqrt{3\sqrt{2}}\) và \(\sqrt{2\sqrt{3}}\)
d) \(\sqrt{10}+\sqrt{17}+1\) và \(\sqrt{61}\)
giúp mk vs ah mk cần gấp
b: Ta có: \(4\sqrt{5}=\sqrt{4^2\cdot5}=\sqrt{80}\)
\(5\sqrt{3}=\sqrt{5^2\cdot3}=\sqrt{75}\)
mà 80>75
nên \(4\sqrt{5}>5\sqrt{3}\)
Tính:
1) \(\sqrt{14-2\sqrt{33}}\)
2) \(\sqrt{12-2\sqrt{35}}\)
3) \(\sqrt{16-2\sqrt{55}}\)
4) \(\sqrt{14-6\sqrt{5}}\)
5) \(\sqrt{17-12\sqrt{2}}\)
6) \(\sqrt{27-12\sqrt{5}}\)
7) \(\sqrt{4+\sqrt{15}}\)
LÀM CHI TIẾT GIÚP MK NHÉ!
1)
\(=\sqrt{\left(\sqrt{11}\right)^2-2.\sqrt{11}.\sqrt{3}+\left(\sqrt{3}\right)^2}\)
\(=\sqrt{\left(\sqrt{11}-\sqrt{3}\right)^2}=\sqrt{11}-\sqrt{3}\)
2)
\(=\sqrt{\left(\sqrt{7}\right)^2-2.\sqrt{7}\sqrt{5}+\left(\sqrt{5}\right)^2}=\sqrt{\left(\sqrt{7}-\sqrt{5}\right)^2}=\sqrt{7}-\sqrt{5}\)
3)
\(=\sqrt{\left(\sqrt{11}\right)^2-2.\sqrt{11}\sqrt{5}+\left(\sqrt{5}\right)^2}=\sqrt{\left(\sqrt{11}-\sqrt{5}\right)}=\sqrt{11}-\sqrt{5}\)
4)
\(=\sqrt{3^2-2.3.\sqrt{5}+\left(\sqrt{5}\right)^2}=\sqrt{\left(3-\sqrt{5}\right)^2}=3-\sqrt{5}\)
5)
\(=\sqrt{3^2-2.3.2\sqrt{2}+\left(2\sqrt{2}\right)^2}=\sqrt{\left(3-2\sqrt{2}\right)^2}=3-2\sqrt{2}\)
1) có bao nhiêu giá trị nguyên của x để biểu thức
\(M=\sqrt{x+4}+\sqrt{2-x}\) có nghĩa
2) so sánh
a) \(\sqrt{33}-\sqrt{17}\) và \(6-\sqrt{15}\)
b) \(4\sqrt{5}\) và \(5\sqrt{3}\)
c) \(\sqrt{3\sqrt{2}}\) và \(\sqrt{2\sqrt{3}}\)
d) \(\sqrt{10}+\sqrt{17}+1\) và \(\sqrt{61}\)
giúp mk nhé mk cần gấp
Bài 1:
Để M có nghĩa thì \(\left\{{}\begin{matrix}x+4\ge0\\2-x\ge0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ge-4\\x\le2\end{matrix}\right.\Leftrightarrow-4\le x\le2\)
Số giá trị nguyên thỏa mãn điều kiện là:
\(\left(2+4\right)+1=7\)
Thực hiện phép tính :
a) \(\sqrt{42-10\sqrt{7}}+\sqrt{33-8\sqrt{17}}\)
b) \(\frac{2}{1+\sqrt{3}}+\frac{1}{2+\sqrt{3}}-\sqrt{\left(1-\sqrt{3}\right)^2}\)
Tính:
\(\sqrt{9-\sqrt{17}}\cdot\sqrt{9+\sqrt{17}}\)
Ta có: \(\sqrt{9-\sqrt{17}}\cdot\sqrt{9+\sqrt{17}}\)
\(=\sqrt{\left(9-\sqrt{17}\right)\left(9+\sqrt{17}\right)}\)
\(=\sqrt{81-17}=\sqrt{64}=8\)
a, \(\sqrt{9\cdot\sqrt{17}}\cdot\sqrt{9+\sqrt{17}}\)
b,\(\sqrt{9\left(3-a\right)^2}vớia>3\)
a) \(\sqrt{9-\sqrt{17}}.\sqrt{9+\sqrt{17}}=\sqrt{81-17}=\sqrt{64}=8\)
b)\(\sqrt{9\left(3-a\right)^2}=3\left|3-a\right|=3\left(a-3\right)\)(vì a > 3)
\(\sqrt{9-\sqrt{17}}.\sqrt{9+\sqrt{17}}\)
\(=\sqrt{\left(\sqrt{9}\right)^2}-\sqrt{\left(\sqrt{17}\right)^2}\)
\(\sqrt{9\left(3-a\right)^2}\)
\(=\sqrt{3^2\left(3-a\right)^2}\)
\(=3\left(3-a\right)\)
\(=3-3a\)