Differentiate y=x^(-1/2)-x

The formula you are given is an equation which is written in terms of x. So we will be differentiating with respect to x. 

When differentiating we take the current power and place that in front of the term. Then we subtract 1 from the power in question. 

Generally the formula is given by y = x^n+x+c. dy/dx = nx^(n-1) + 1 + 0 

So now lets apply this to our question. 

y = x^(-1/2)-x

Bring the current power down and subtract one from the power so: 

dy/dx = -1/2x^(-3/2) - 1