Question

Charisma has simplified an expression as shown below.


In which step has she made an error?

Answer 1

Answer:

Step 4, because √2 + √8 ≠ √10

Step-by-step explanation:

Answer 2

Answer:

(Step 4)

Step-by-step explanation:

The main concept behind this that:

$\sqrt{a} + \sqrt{b} \neq \sqrt{a+b}$  for all a ,b except either of a and b or both equals to zero.

Proof:

Let $\sqrt{a} + \sqrt{b} = \sqrt{a+b}$

Squaring both the sides we get that:

a + b + 2√a√b = a + b

⇒ 2√a√b =0

⇒ Either a = 0 or b=0 or both a and b =0, which contradicts given condition

hence proved by contradiction.

⇒ $\sqrt{2} +\sqrt{8} \neq \sqrt{10}$

#SPJ2