Sun	Mon	Tue	Wed	Thu	Fri	Sat
23	24	25	26	27	28	1
2	3	4	5	6	7	8
9	10	11	12	13	14	15
16	17	18	19	20	21	22
23	24	25	26	27	28	29
30	31	1	2	3	4	5

Back to Main Page

Multiple Choice Questions

If x 1 x 2 then the value of x 4 1 x 4 is ........

Quantitative Aptitude (CGL) Algebra

Download Solution PDF

If x+ 1/x=2,then the value of x^4 -1/x^4 is?

छोटे Courses बड़े Results

Master Algebra

Prepare through Micro-courses

Try Now

Explanation:

x + 1/x)² = x² + 1/x² + 2
=> 2² = x² + 1/x² + 2
=> x² + 1/x² = 4–2 = 2 . . . . . . . .(1)
(x - 1/x)² = x² + 1/x² -2
=> ( x-1/x)² = 2 - 2 = 0
=> (x-1/x) = 0 . . . . . . . . . .(2)
Now, x^4 - 1/x^4 = ( x² + 1/x²) ( x² - 1/x²)
= 2 ( x + 1/x) ( x-1/x)
= 2 * 2 * 0 ( by (1) & (2)
= > x^4 - 1/x^4 = 0 . . . . . . . .Ans

Report error