Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
The value of $$(52+6\sqrt{43})^{3/2} - (52-6\sqrt{43})^{3/2}$$ is
We are given the expression:Β $$(52+6\sqrt{43})^{3/2} - (52-6\sqrt{43})^{3/2}$$
Now, the term $$52+6\sqrt{43}$$ can be rewritten as:
$$52+6\sqrt{43}=9+43+2*3*\sqrt{43}=(3+\sqrt{43})^2$$
Similarly, we can rewrite the termΒ $$52-6\sqrt{43}$$ as:
$$52-6\sqrt{43}=9+43-2*3*\sqrt{43}=(3-\sqrt{43})^2$$ or $$(\sqrt{43}-3)^2$$
But whenever we have $$\sqrt{52-6\sqrt{43}}$$, the correct answer would be $$(\sqrt{43}-3)$$ as the square root is defined in mathematics to give only a positive answer due to functional constraints put on it.
Now, we had:Β $$(52+6\sqrt{43})^{3/2} - (52-6\sqrt{43})^{3/2}$$
$$=(\sqrt{52+6\sqrt{43}})^3 - (\sqrt{52-6\sqrt{43}})^3$$
$$=(3+\sqrt{43})^3-(\sqrt{43}-3)^3$$
$$=(27+\sqrt{43}^3+27\sqrt{43}+9*43)-(-27+\sqrt{43}^3+27\sqrt{43}-9*43)$$
$$=2(27+9*43)$$
$$=828$$
Hence, Option D is correct.
Click on the Email βοΈ to Watch the Video Solution
Predict your JEE Main percentile, rank & performance in seconds
Educational materials for JEE preparation