Please answer this...
Attachments:
Answers
Answered by
8
Answer:
x³ + (1/x³) = 52
Step-by-step explanation:
Given: x² + (1/x²) = 14
It can be written as,
⇒ x² + (1/x²) = 16 - 2
⇒ x² + (1/x²) + 2 = 16
⇒ (x + 1/x)² = 16
⇒ x + 1/x = 4
On cubing both sides, we get
⇒ (x + 1/x)³ = 4³
⇒ x³ + 1/x³ + 3(x + 1/x) = 64
⇒ x³ + 1/x³ + 3(4) = 64
⇒ x³ + 1/x³ + 12 = 64
⇒ x³ + 1/x³ = 52
Hope it helps!
sharishk2003:
what is the formula for a^3 +b^3
a^3 + b^3 = (a + b)(a^2 - ab + b^2)
but u have not chosen for
The question is asked to find x^3 + 1/x^3 !
what is the formula for (a + b)^3
a^3 + b^3 + 3ab(a + b )
oh thank u
Welcome
Answered by
1
x² + 1/x² = 14
(x + 1/x)² - 2(x)(1/x) = 14
(x + 1/x)² = 14+2
(x + 1/x)² = 16
x + 1/x = √16
x + 1/x = 4
-----------------
(x³ + 1/x³) = (x + 1/x)³ - 3(x.1/x) (x+1/x)
= 4³ - 3(4)
= 64 - 12
= 52.
tq...so much
Similar questions