Advertisements
Advertisements
प्रश्न
If `3x - (1)/(3x) = 9`; find the value of `27x^3 - (1)/(27x^3)`.
उत्तर
`3x - (1)/(3x) = 9`
Using `("a" - (1)/"a")^3`
= `"a"^3 - (1)/"a"^3 - 3("a" - 1/"a")`, we get :
`(3x - 1/(3x))^3`
= `(3x)^3 - (1/(3x))^3 -3(3x - 1/(3x))`
⇒ 729 = `27x^3 - (1)/(27x^3) - 3(9)`
⇒ `27x^3 - (1)/(27x^3)`
= 729 + 27
= 756.
APPEARS IN
संबंधित प्रश्न
Expand.
(52)3
Find the cube of : `( 3a - 1/a ) (a ≠ 0 )`
If `a^2 + 1/a^2` = 18; a ≠ 0 find :
(i) `a - 1/a`
(ii) `a^3 - 1/a^3`
If a + 2b = 5; then show that : a3 + 8b3 + 30ab = 125.
Expand : (3x + 5y + 2z) (3x - 5y + 2z)
If a ≠ 0 and `a - 1/a` = 4 ; find : `( a^3 - 1/a^3 )`
If `x + (1)/x = 5`, find the value of `x^2 + (1)/x^2, x^3 + (1)/x^3` and `x^4 + (1)/x^4`.
If `x^2 + (1)/x^2 = 18`; find : `x^3 - (1)/x^3`
Find the volume of the cube whose side is (x + 1) cm
(p + q)(p2 – pq + q2) is equal to _____________
