Question

Pls solve and I will mark u brainiest!

Answer 1

Step-by-step explanation:

Q4:

Given,

a - 1/a = 1 -------(1)

Squaring,

a² - 2 + 1/a² = 1

a² + 1/a² = 3

a² + 2 + 1/a² = 5

(a + 1/a)² = 5

a + 1/a = √5 --------(2)

(1) × (2)

(a - 1/a)(a + 1/a) = √5

a² - 1/a² = √5

Q5:

Given,

a + b + c = 8

ab + bc + ca = 4

But,

(a + b + c)² = a² + b² + c² + 2(ab + bc + ca)

So,

8² = a² + b² + c² + 2×4

64 - 8 = a² + b² + c²

a² + b² + c² = 56