87.3k views
5 votes
Rationalise the denominator 1/5-root 2

User Michal M
by
4.1k points

1 Answer

1 vote

Answer:

the rationalized form of the denominator 1/(5^(1/2)-2) is (x+2)/((x-2)(x-1)(x+1)).

Explanation:

Correctly me if im wrong. To rationalize the denominator of the fraction 1/(5^(1/2)-2), we can use the conjugate of the denominator. The conjugate of a+b is a-b, so the conjugate of 5^(1/2)-2 is 5^(1/2)+2. We can then multiply the numerator and denominator of the fraction by the conjugate to obtain:

1/(5^(1/2)-2) * (5^(1/2)+2)/(5^(1/2)+2)

= (1*(5^(1/2)+2)) / ((5^(1/2)-2)*(5^(1/2)+2))

= (5^(1/2)+2) / (5^2 - 2*5^(1/2) - 4)

Notice that we can further simplify this expression by substituting 5^(1/2) with x and expanding the denominator:

(5^(1/2)+2) / (5^2 - 2*5^(1/2) - 4)

= (x+2) / (x^2 - 2x - 4)

= (x+2) / (x-2)(x+2)

The denominator of this expression can be further simplified by factoring out x-2, which gives us:

(x+2) / (x-2)(x+2)

= (x+2) / (x-2)(x-2 + 4)

= (x+2) / (x-2)(x^2 - 2x + 4 - 4)

= (x+2) / (x-2)(x^2 - 2x)

= (x+2) / (x-2)((x-1)(x+1))
Finally, we can use the fact that x-1 and x+1 are factors of x^2-2x, which means that we can factor out x-1 and x+1 from the denominator to obtain the fully simplified expression:
(x+2) / (x-2)(x^2 - 2x)

= (x+2) / (x-2)(x-1)(x+1)

= (x+2) / ((x-2)(x-1)(x+1))

Therefore, the rationalized form of the denominator 1/(5^(1/2)-2) is (x+2)/((x-2)(x-1)(x+1)).

User Shu Suzuki
by
4.4k points