Advertisements
Advertisements
प्रश्न
If `3x - (1)/(3x) = 9`; find the value of `27x^3 - (1)/(27x^3)`.
Advertisements
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
If a2 + `1/a^2 = 47` and a ≠ 0 find :
- `a + 1/a`
- `a^3 + 1/a^3`
If a + 2b = 5; then show that : a3 + 8b3 + 30ab = 125.
The sum of two numbers is 9 and their product is 20. Find the sum of their (i) Squares (ii) Cubes.
If a ≠ 0 and `a - 1/a` = 4 ; find : `( a^3 - 1/a^3 )`
If `"a" + (1)/"a" = "p"`; then show that `"a"^3 + (1)/"a"^3 = "p"("p"^2 - 3)`
If x3 + y3 = 9 and x + y = 3, find xy.
If x + 2y = 5, then show that x3 + 8y3 + 30xy = 125.
Evaluate the following :
(5.45)3 + (3.55)3
If `"a" + 1/"a"` = 6, then find the value of `"a"^3 + 1/"a"^3`
(p + q)(p2 – pq + q2) is equal to _____________
