Rationalise the denominator of 1/(4 + sqrt(3))

This denominator is irrational because it contains a surd. To rationalise the denominator we multiply the numerator and denominator by the conjugate of the denominator. In this case, the conjugate of the denominator is 4-sqrt(3)Therefore we get 1/(4 + sqrt(3)) * (4 - sqrt(3))/(4 - sqrt(3)). This simplifies to: (4 - sqrt(3))/(16 + 4sqrt(3) - 4sqrt(3) -3) and therefore: (4 - sqrt(3))/13

GM

Related Maths GCSE answers

All answers ▸

Billy wants to buy 10kg of the same oranges. Type A comes in bags of 1.25 kg and costs £1.50. Type B comes in bags of 5kg and used to cost £6.60 but are now 15% off. Which type is more worth it for Billy and how much does it cost?


How do I a differentiate a cosine function?


Prove that the difference of any two consecutive square numbers is odd


Clare buys some shares for $50x. Later, she sells the shares for $(600 + 5x). She makes a profit of x% (a) Show that x^2 + 90x − 1200 = 0