fixes[#310] Update space complexity chapter formatting (remove $)

fixes[#310]

Author: Kinshu-Learner

en/complexity/space-complexity.md

@@ -11,7 +11,7 @@ Space complexity is the amount of memory that a program takes to run with respec
 In this chapter, we will learn about the following space complexities:
 
 - O(n) - linear space complexity
-- O($n^2$) - quadratic space complexity
+- O(n^2) - quadratic space complexity
 - O(1) - constant space complexity 
 
 ### **Linear Space Complexity: O(n)**
@@ -33,7 +33,7 @@ console.log(squareElements(myArray)); // Output: [1, 4, 9, 16, 25]
 In this example, the space complexity is O(n) because the result array grows in proportion to the size of the input array `arr`.
 
 
-### Quadratic Space Complexity (O($n^2$))
+### Quadratic Space Complexity (O(n^2))
 The memory required grows proportionally to the square of the input size.
 
 **Example:**
@@ -70,3 +70,4 @@ printCube(3); // Output: 27
 ```
 
 The space required does not depend on the input size.
+