Tính giá trị biểu thức:
\(\sqrt{22-12\sqrt{2}}+\sqrt{6+4\sqrt{2}}\)
Tính giá trị bthuc
\(\sqrt{6-4\sqrt{ }2}+\sqrt{22-12\sqrt{ }2}\)
\(=\sqrt{\left(2-\sqrt{2}\right)^2}+\sqrt{\left(3\sqrt{2}-2\right)^2}\\ =2-\sqrt{2}+3\sqrt{2}-2=2\sqrt{2}\)
\(\sqrt{6-4\sqrt{2}}+\sqrt{22-12\sqrt{2}}\)
\(=\sqrt{\left(\sqrt{2}-2\right)^2}+\sqrt{\left(3\sqrt{2}-2\right)^2}\)
\(=2-\sqrt{2}+3\sqrt{2}-2=2\sqrt{2}\)
\(\sqrt{6-4\sqrt{2}}+\sqrt{22-12\sqrt{2}}\)
\(=2-\sqrt{2}+3\sqrt{2}-2\)
\(=2\sqrt{2}\)
Tính giá trị biểu thức:
\(A=\sqrt{6+\sqrt{24}+\sqrt{12}+\sqrt{8}}-\sqrt{4+2\sqrt{3}}\)
\(A=\sqrt{6+\sqrt{24}+\sqrt{12}+\sqrt{8}}-\sqrt{4+2\sqrt{3}}\)
\(=\sqrt{6+2\sqrt{6}+2\sqrt{3}+2\sqrt{2}}+\sqrt{\left(\sqrt{3}+1\right)^2}\)
\(=\sqrt{\left(1+\sqrt{2}+\sqrt{3}\right)^2}+\sqrt{3}+1\)
\(=1+\sqrt{2}+\sqrt{3}+\sqrt{3}+1=\sqrt{2}+2\sqrt{3}+2\)
tính giá trị biểu thức
a, \(\sqrt{6+2\sqrt{4-2\sqrt{3}}}\)
b, \(\sqrt{12-6\sqrt{3}}\)
c, \(\sqrt{6-4\sqrt{2}+\sqrt{22-12\sqrt{2}}}\)
a) \(\sqrt{6+2\sqrt{4-2\sqrt{3}}}\)
\(=\sqrt{6+2\sqrt{\left(\sqrt{3}-1\right)^2}}\)
\(=\sqrt{6+2\left(\sqrt{3}-1\right)}\)
\(=\sqrt{6+2\sqrt{3}-2}\)
\(=\sqrt{4+2\sqrt{3}}\)
\(=\sqrt{\left(\sqrt{3}+1\right)^2}\)
\(=\sqrt{3}+1\)
b) \(\sqrt{12-6\sqrt{3}}\)
\(=\sqrt{9-2\cdot3\cdot\sqrt{3}+3}\)
\(=\sqrt{\left(\sqrt{9}-\sqrt{3}\right)^2}\)
\(=3-\sqrt{3}\)
c) \(\sqrt{6-4\sqrt{2}+\sqrt{22-12\sqrt{2}}}\)
\(=\sqrt{6-4\sqrt{2}+\sqrt{\left(\sqrt{18}-2\right)^2}}\)
\(=\sqrt{6-4\sqrt{2}+\sqrt{18}-2}\)
\(=\sqrt{4-4\sqrt{2}+3\sqrt{2}}\)
\(=\sqrt{4-\sqrt{2}}\)
Tính giá trị biểu thức:\(\frac{\sqrt{5+\sqrt{3}}+\sqrt{5-\sqrt{3}}}{\sqrt{5\sqrt{22}}}\)+\(\sqrt{11-6\sqrt{2}}\)
tính giá trị biểu thức
a)\(\sqrt{3+2\sqrt{2}}+\sqrt{\left(\sqrt{2}-2\right)^2}\)
b)\(\dfrac{1}{5}\sqrt{50}-2\sqrt{96}-\dfrac{\sqrt{30}}{\sqrt{15}}+12\sqrt{\dfrac{1}{6}}\)
c)\(\left(\dfrac{5-\sqrt{5}}{\sqrt{5}}-2\right)\left(\dfrac{4}{1+\sqrt{5}}+4\right)\)
a) \(\sqrt{3+2\sqrt{2}}+\sqrt{\left(\sqrt{2}-2\right)^2}\)
\(=\sqrt{\left(\sqrt{2}\right)^2+2\sqrt{2}\cdot1+1^2}+\left|\sqrt{2}-2\right|\)
\(=\sqrt{\left(\sqrt{2}+1\right)^2}-\left(\sqrt{2}-2\right)\)
\(=\left|\sqrt{2}+1\right|-\sqrt{2}+2\)
\(=\sqrt{2}+1-\sqrt{2}+2\)
\(=3\)
b) \(\dfrac{1}{5}\sqrt{50}-2\sqrt{96}-\dfrac{\sqrt{30}}{\sqrt{15}}+12\sqrt{\dfrac{1}{6}}\)
\(=\dfrac{1}{5}\cdot5\sqrt{2}-2\cdot4\sqrt{6}-\sqrt{\dfrac{30}{15}}+\sqrt{\dfrac{144}{6}}\)
\(=\sqrt{2}-8\sqrt{6}-\sqrt{2}+2\sqrt{6}\)
\(=-8\sqrt{6}+2\sqrt{6}\)
\(=-6\sqrt{6}\)
c) \(\left(\dfrac{5-\sqrt{5}}{\sqrt{5}}-2\right)\left(\dfrac{4}{1+\sqrt{5}}+4\right)\)
\(=\left[\dfrac{\sqrt{5}\left(\sqrt{5}-1\right)}{\sqrt{5}}-2\right]\left[\dfrac{4\left(1-\sqrt{5}\right)}{\left(1+\sqrt{5}\right)\left(1-\sqrt{5}\right)}+4\right]\)
\(=\left(\sqrt{5}-1-2\right)\left(\dfrac{4\left(1-\sqrt{5}\right)}{1-5}+4\right)\)
\(=\left(\sqrt{5}-3\right)\left(\sqrt{5}-1+4\right)\)
\(=\left(\sqrt{5}-3\right)\left(\sqrt{5}+3\right)\)
\(=\left(\sqrt{5}\right)^2-3^2\)
\(=-4\)
a) \(\sqrt[]{3+2\sqrt[]{2}}+\sqrt[]{\left(\sqrt[]{2}-2\right)^2}\)
\(=\sqrt[]{2+2\sqrt[]{2}.1+1}+\left|\sqrt[]{2}-2\right|\)
\(=\sqrt[]{\left(\sqrt[]{2}+1\right)^2}+\left(2-\sqrt[]{2}\right)\) \(\left(\left(\sqrt[]{2}\right)^2=2< 2^2=4\right)\)
\(=\left|\sqrt[]{2}+1\right|+2-\sqrt[]{2}\)
\(=\sqrt[]{2}+1+2-\sqrt[]{2}\)
\(=3\)
1.Giá trị biểu thức
\(\sqrt{15-6\sqrt{6}}\) + \(\sqrt{15+6\sqrt{6}}\) bằng
A. 3
B. 12\(\sqrt{6}\)
C. \(\sqrt{30}\)
D. 6
2.Biểu thức \(\sqrt{2}.\sqrt{8}\) có giá trị là :
A. 4
B. một kết quả khác
C. 16
D. -4
3. Giá trị của \(\sqrt{\sqrt{16}}\) bằng :
A. 16
B. 4
C. 2
D. 8
4. Biểu Thức \(\sqrt{-2x+3}\) có nghĩa khi:
A. x ≥ \(\dfrac{2}{3}\)
B. x ≤ \(\dfrac{3}{2}\)
C. x ≥ \(\dfrac{3}{2}\)
D. x ≤ \(\dfrac{2}{3}\)
5.\(\sqrt{^{\left(2x+1\right)^2}}\) bằng:
A. |2x+1|
B. -(2x+1)
C. |-2x+1|
D. 2x+1
Tính giá trị của biểu thức:
\(\sqrt{2+\sqrt{3+\sqrt[3]{4+5\sqrt[5]{6+7\sqrt[7]{8+9\sqrt[9]{10+11\sqrt[11]{12}}}}}}}\)
Tính giá trị của biểu thức
\(\left(4\sqrt{3}-2\sqrt{2}\right)\left(\sqrt{4\sqrt{6}+8\sqrt{3}+4\sqrt{2}+18}-2\right)\)
\(=\left(4\sqrt{3}-2\sqrt{2}\right)\left(\sqrt{12+4\sqrt{6}+2+8\sqrt{3}+4\sqrt{2}+4-2}\right)\\ =\left(4\sqrt{3}-2\sqrt{2}\right)\left(\sqrt{\left(2\sqrt{3}+\sqrt{2}\right)^2+4\left(2\sqrt{3}+\sqrt{2}\right)+4-2}\right)\\ =\left(4\sqrt{3}-2\sqrt{2}\right)\left(\sqrt{\left(2\sqrt{3}+\sqrt{2}+2\right)^2-2}\right)\\ =\left(4\sqrt{3}-2\sqrt{2}\right)\left(2\sqrt{3}+\sqrt{2}\right)=20\)
bài 1)tính giá trị biểu thức
a)M=\(\frac{\sqrt{2}+\sqrt{3}+\sqrt{6}+\sqrt{8}+4}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)
b)N=\(\sqrt{2+\sqrt{3}+\sqrt{4-2\sqrt{3}}-\sqrt{21-12\sqrt{3}}}\)