derivatives/ rules for differentiation

[gcfan4life1023]

im suppose to find dy/dx and d^2y/dx^2 using the rules for differentiations . The seven rulles include derivative of a constant function, power rule for positive interger powers of x, the constant multiple rule, the sum and difference rule, the product rule,the quotient rule, and the power rule for negative integer powers of x, but i have no clue how to apply the rules or what im doing he didnt teach us how to do it he just assigned us #1-20 and i have no clue where to start an example of my problems is
y= -x^2 + 3 can somebody please just tell me how to start it maybe i can prolly take it from there

 

[Guest]

to start with your problem.
y= -x^2 + 3

dy/dx = (-2)x^1

dy/dx = -2x

then...

d^2y/dx^2 = -2

the theory...
if y = ax^n, then
dy/dx = na x^(n-1) where a and n are constants.

Does this help?