Question

show that 1n( x^3 - 4x) - 1 n( x^2 -2x) = 1n(x+2)

Answer 1

Answer:

x

3

−4x

2

−x+1=(x−2)

3

using identify (a−b)

3

=a

3

−b

3

−3a

2

b+3ab

2

we get

x

3

−4x

2

−x+1=x

3

−8−6x

2

+12x

6x

2

−4x

2

−x−12x+1+8=0

2x

2

−13x+9=0

x=

4

+13±

169−72

=

4

13±

97

Hence x=

4

13+

97

&

4

13−

97

solution