Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $ p^4 = 4354 -\frac{1}{p^4}$ then the value of $p^3 - \frac{1}{p^3}$ can  be :

Options:

536

436

416

516

Correct Answer:

536

Explanation:

If x4 + \(\frac{1}{x^4}\) = a

then x2 + \(\frac{1}{x^2}\) = \(\sqrt {a + 2}\) = b

and x - \(\frac{1}{x}\) = \(\sqrt {b - 2}\)

If $ p^4 = 4354 -\frac{1}{p^4}$

then the value of $p^3 - \frac{1}{p^3}$ = ?

If $ p^4 = 4354 -\frac{1}{p^4}$

$ p^4 + \frac{1}{p^4}= 4354 $

p2 + \(\frac{1}{p^2}\) = \(\sqrt {4356 + 2}\) = 66

and p - \(\frac{1}{p}\) = \(\sqrt {66 - 2}\) = 8

If x - \(\frac{1}{x}\)  = n

then, $x^3 -\frac{1}{x^3}$ = n3 + 3 × n

$p^3 - \frac{1}{p^3}$ = 83 + 3 × 8

$p^3 - \frac{1}{p^3}$ = 512 + 24= 536