Question

evaluate 3-√5. ÷ 3+√5 given that √5 =2.236​

Answer 1

Answer:

. 145912911

Step-by-step explanation:

3-√5÷3+√5

=0.764÷5.236

=0.145912911

Answer 2

Given:

$\frac{3 - \sqrt{5} }{3 + \sqrt{5} }$

Simplification:

On Rationalisation:

$= \frac{(3 - \sqrt{5})(3 - \sqrt{5}) }{(3 + \sqrt{5})(3 - \sqrt{5})}$

$= \frac{9 + 5 - 6 \sqrt{5} }{9 - 5}$

$= \frac{14 - 6 \sqrt{5} }{4}$

$= \frac{14 - 6(2.236)}{4}$

$= \frac{14 - 13.416}{4}$

$= \frac{0.584}{4} \\ = 0.146$

Answer: 0.146.

Identities Used:

1. (a - b)² = a² + b² - 2ab.

2. (a + b)(a - b) = a² - b².