# I need some explain about 5 + 2 =13

Tell us what’s happening: I can pass the challenge but I don’t understand why 5 + 2 = 13
Describe your issue in detail here.

``````  **Your code so far**
``````
``````
// Setup
function abTest(a, b) {
// Only change code below this line
if (a < 0 || b < 0){
return undefined;
}

// Only change code above this line

return Math.round(Math.pow(Math.sqrt(a) + Math.sqrt(b), 2));
}

console.log(abTest(6,2));
``````
``````  **Your browser information:**
``````

User Agent is: `Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36`

Challenge: Return Early Pattern for Functions

This lesson is to show you that when you reach the return statement you’d finish the execution of funtion.

``````if (a < 0 || b < 0){
return undefined;
}
``````

by the end of the return line, the execution of the rest will be terminated and this part won’t get compiled

``````return Math.round(Math.pow(Math.sqrt(a) + Math.sqrt(b), 2));
``````

PS:

The `Math.sqrt()` function returns the square root of a number, that is
The `Math.pow()` function returns the `base` to the `exponent` power, as in `base^exponent` .