Week 4 - Tutorial 4 - Doubt

[Zohair Merchant]

Hi all,

In Week 4, Tutorial 4, we have the equation 88x / 40 - x^2 / 40 + 30

Doubt:

Here I have a doubt regarding this part of the equation:      - x^2 / 40.

When we computed the value of x = 44, we substituted it in this part of the equation as: 

- ( 44 * 44 ) / 40.

But considering it is -x^2, why isn't it taken as ( - 44 * - 44 ) / 40. Doesn't minus x mean minus 44?

Why is the minus taken separately? In what situations should we consider minus as separate and in what conditions should we take minus with the variable?

Regards,

Zohair

 

[DHARMA TEJA GODUMALA]

Don't confuse much, just observe below you will understand

 (X*X)=   X^2

-(X*X) =  - X^2

(-X * -X) =  X^2

(-X* X) = -X^2