If x + √15 = 4, then x + \(\frac{1}{x}\) = A. 2B. 4C. 8D. 1

1.	If x + √15 = 4, then x + \(\frac{1}{x}\) = A. 2B. 4C. 8D. 1
Answer» Given x +√15 = 4 x = 4 - √15 \(\frac{1}{x}\) = 1/(4 - √15) = (4 + √15) / 16 -15 = 4 + √15 So, x + \(\frac{1}{x}\) = 4 - √15 + 4+√15 = 8

Answer»

Given x +√15 = 4

x = 4 - √15

\(\frac{1}{x}\) = 1/(4 - √15) = (4 + √15) / 16 -15 = 4 + √15

So, x + \(\frac{1}{x}\) = 4 - √15 + 4+√15 = 8

Discussion

The simplest rationalising factor of 2√5 - √3 isA. 2√5 + 3B. 2√5 + C. √5 + √3D. √5 - √3
The simplest rationalising factor of √3+ √5 isA. √3 - 5B. 3 - √5C. √3 - √5D. √3 + √5
Simplify:(√8 – √2) (√8 + √2)
Simplify each of the following:(i) \(\sqrt[3]{4}\) x \(\sqrt[3]{16}\)(ii) \(\frac{\sqrt[4]{1250}}{\sqrt[4]{2}}\)
Simplify:(3 + √3)(5 - √2)
Simplify:(3 + √3) (3 – √3)
Simplify:(4 + √7) (3 + √2)
Simplify:(√5 – √2) (√5 + √2)
Simplify:(√3 + √7)2
Simplify:(√5 – √3)2.