Question

Given 2x^2=-8, x is A.-2 B. 2 C. 2i or -2i D. 4i or -4i

Answer 1

Answer:

The value of x is $\bold{\pm 2 i}$

Given:

$2 x^{2}=-8$

Solution:

In this problem, we need to find the variable ‘x’ where the value of the x will change according to the conditions provided in the problem. The value of the variable of determined with the help of the constants whose values never change.

Now, in the given problem, we have to bring the constants on one side and variable on one side.

So, on bring the 2 to denominator,

$\Rightarrow x^{2}=-\frac{8}{2}$

$\Rightarrow x^{2}=-4$

On taking square root,

$\Rightarrow x=\sqrt{-4}$

Since, the square is always positive, we cannot get a number with negative sign as a square. So, the square root of the negative number becomes an imaginary number because that number doesn't exist.

$\Rightarrow x=\sqrt{(-1) \times 4}$

$\therefore x=\pm 2 i$

Answer 2

Answer:

2i or -2i

Step-by-step explanation:

2x² = -8     First, clear x.

x² = -8/2    Solve

x² = -4        Now, eliminate the square of x by solving the square root of -4.

x = √-4

x = 2i or -2i Is an imaginary number.