Bài 9: Căn bậc ba
Các câu hỏi tương tự
Thực hiện các phép tính sau :
a)A=\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\) b)B=\(\left(2-\sqrt{3}\right).\sqrt[3]{26+15\sqrt{3}}\) c)C=\(\sqrt[3]{3+\sqrt{9+\dfrac{125}{27}}}-\sqrt[3]{-3+\sqrt{9+\dfrac{125}{7}}}\)
Tính
a.A=\(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\)
b.B=\(\sqrt[3]{3+\sqrt{9+\dfrac{125}{7}}}-\sqrt[3]{-3+\sqrt{9+\dfrac{125}{7}}}\)
c.C=\(\sqrt[3]{26+15\sqrt{3}}.\left(2-\sqrt{3}\right)+\sqrt[3]{9+\sqrt{80}}+\sqrt[3]{9-\sqrt{80}}\)
a) \(\sqrt[3]{5-\sqrt{17}}+\sqrt[3]{5+\sqrt{17}}\)
b) \(\dfrac{1}{\sqrt[3]{4-\sqrt{15}}}+\sqrt[3]{4-\sqrt{15}}\)
c) \(\dfrac{\sqrt[3]{a^4}+\sqrt[3]{a^2b^2}+\sqrt[3]{b^4}}{\sqrt[3]{a^2}+\sqrt[3]{ab}+\sqrt[3]{b^2}}\)
Rút gọn các biểu thức sau
Bài 1: Tính
A= \(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\)
B=\(\sqrt[3]{9+4\sqrt{5}}+\sqrt[3]{9-4\sqrt{5}}\)
Bài 2: PTTNT:
a) \(\sqrt[3]{15}-\sqrt[3]{21}\)
b)\(\sqrt[3]{3}-3\)
c)\(\sqrt[3]{a^2x}+\sqrt[3]{b^2x}\)
1.Chứng minh:\(\dfrac{a+\sqrt{2+\sqrt{5}.}\sqrt{\sqrt{9-4\sqrt{5}}}}{3\sqrt{2-\sqrt{5}}.\sqrt[3]{\sqrt{9+4\sqrt{5}-}3\sqrt{a^2}+\sqrt[3]{a}}}\)=\(-\sqrt[3]{a}-1\)
2.Rút gọn: \(\left(\dfrac{a^3\sqrt[]{a}-2a^3\sqrt{b}+\sqrt[3]{a^2}-\sqrt[3]{b}}{\sqrt[3]{a^2-\sqrt[3]{ab}}}+\dfrac{\sqrt[3]{a^2b}-\sqrt[3]{ab^2}}{\sqrt[3]{a}-\sqrt[3]{b}}\right)1\dfrac{1}{\sqrt[3]{a^2}}\)
cho x =\(\dfrac{7-4\sqrt{3}}{\sqrt[3]{26-15\sqrt{3}}}-\sqrt[3]{26+15\sqrt{3}}\)
tính A= \(\dfrac{x^6+x^4+4x^2}{40\left(x^4+4x^2-144\right)}\)
1.Tính các giá trị biểu thức:
a.\(x=\sqrt[3]{5+2\sqrt{3}}+\sqrt[3]{5-2\sqrt{3}}\)
b.\(x=\sqrt[3]{\sqrt{5}+2}-\sqrt[3]{\sqrt{5}-2}\)
c.\(x=\sqrt[3]{182+\sqrt{33125}}+\sqrt[3]{182-\sqrt{33125}}\)
d.\(x=\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
Rút gọn biểu thức
\(M=\sqrt[3]{26+15\sqrt{3}}.\left(2-\sqrt{3}\right)+\sqrt[3]{9+\sqrt{80}}+\sqrt[3]{9-\sqrt{80}}\)
Rút gọn các biểu thức:
a) A frac{sqrt[3]{135}}{sqrt[3]{5}}-sqrt[3]{54}sqrt[3]{4}
b) B left(frac{1}{2}sqrt[3]{2}-frac{1}{4}sqrt[3]{16}right).sqrt[3]{4}
c) C sqrt[3]{left(sqrt{2}+1right)left(3+2sqrt{2}right)}
d) D sqrt[3]{3+3sqrt[3]{2}+3sqrt[3]{4}}
e) E sqrt[3]{2+sqrt{5}}+sqrt[3]{2-sqrt{5}}
Đọc tiếp
Rút gọn các biểu thức:
a) A= \(\frac{\sqrt[3]{135}}{\sqrt[3]{5}}-\sqrt[3]{54}\sqrt[3]{4}\)
b) B= \(\left(\frac{1}{2}\sqrt[3]{2}-\frac{1}{4}\sqrt[3]{16}\right).\sqrt[3]{4}\)
c) C= \(\sqrt[3]{\left(\sqrt{2}+1\right)\left(3+2\sqrt{2}\right)}\)
d) D= \(\sqrt[3]{3+3\sqrt[3]{2}+3\sqrt[3]{4}}\)
e) E= \(\sqrt[3]{2+\sqrt{5}}+\sqrt[3]{2-\sqrt{5}}\)