Question

helpz

$\quad \sf {x}^{2} + 4 = 0$

find value of x ​

Answer 1

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Answer:  $\textsf{2i and -2i}$

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Given:  $\textsf{x}^2\textsf{ + 4 = 0}$

Find: $\textsf{The value of x}$

Solution:  In order to find the value of x we must isolate x by itself and it will produce the result.  In this case we need to subtract 4 from both sides and square root both sides in order to isolate x.

Subtract 4 from both sides

• $\textsf{x}^2\textsf{ + 4 - 4 = 0 - 4}$

• $\textsf{x}^2\textsf{ = 0 - 4}$

• $\textsf{x}^2\textsf{ = - 4}$

Square root both sides

• $\sqrt{\textsf{x}^2}\textsf{ = }\sqrt{\textsf{- 4}}$

• $\textsf{x}\textsf{ = }\sqrt{\textsf{- 4}}$

• $\textsf{x}\textsf{ = }\sqrt{\textsf{ 2}^2\textsf{ * (i)}^2}}$

• $\textsf{x}\textsf{ = }\pm\textsf{2i}$

After completing all of the step we are able to determine that x is equal to both 2i and -2i.

Answer 2

Solution :

Given,

• x² + 4 = 0

Aim :

• To find value of x.

Inorder to calculate the value of x we would transpose the 4 which is in L.H.S. to R.H.S. (Remember that sign would be changed in negative).

>> x² = -4

>> √x² = √-4

>> x = ±2

Therefore,

• Value of x is 2 and -2.