Advertisements
Advertisements
Question
If `"r" - (1)/"r" = 4`; find : `"r"^4 + (1)/"r"^4`
Sum
Advertisements
Solution
`("r"^2 + 1/"r"^2)^2`
= `"r"^4 + (1)/sqrt(4) + 2`
⇒ (18)2 = `"r"^4 + (1)/"r"^4 + 2`
⇒ `"r"^4 + (1)/"r"^4`
= 324 - 2
= 322.
shaalaa.com
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
if `x^2 + 1/x^2 = 79` Find the value of `x + 1/x`
Evaluate of the following:
463+343
If a2 - 3a + 1 = 0, and a ≠ 0; find:
- `a + 1/a`
- `a^2 + 1/a^2`
Use the direct method to evaluate :
(3b−1) (3b+1)
Evaluate: 20.8 × 19.2
Evaluate the following without multiplying:
(999)2
If m - n = 0.9 and mn = 0.36, find:
m2 - n2.
If `"a"^2 + (1)/"a"^2 = 14`; find the value of `"a" + (1)/"a"`
Which one of the following is a polynomial?
Factorise the following:
25x2 + 16y2 + 4z2 – 40xy + 16yz – 20xz
