Question

if X square + 1 by x square is equal to 14 find the value of x cube + 1 by x cube​

Answer 1

Answer:

we know that 2*x*1/x = 2---(1)

x² + 1/x² =14

add bothsides 2

x²+1/x² +2 = 14+2

x² +1/x² +2 *x*1/x = 16 from (1)

(x+1/x)² =16 ---(2)

x+1/x = 4 or -4

now

if we x+1/x =4

i)x³ +1/x³ = (x+1/x) [ x²+1/x² -x*1/x]

= 4* [ 14 -1]

= 4* 13

=52

ii) if take x+1/x = -4

x³+1/x³ = (-4) [14 -1]

=(-4) *13

=-52