Math Is Fun Forum

karl

Guest

Differentiate the following with respect to x

Differentiate the following   with respect to x

a)    y =  17x³  -  8x²  + 37

                             8
b)    y =  8 (7x  -3)                 using the Function of a Function rule

any help please  getting rele stuck with these two???

Thanks
karl

Daniel123

Member

Registered: 2007-05-23

Posts: 663

Re: Differentiate the following with respect to x

For part a), just differentiate each term individually.

For part b), use the chain rule (or, as you call it, the "function of a funtion rule").
Remember, the chain rule states that if

, then

. In other words, differentiate the whole bracket by bringing the power down and decreasing the power by one, and then multiply it by the derivative of what's inside (you can always leave a constant on the outside where it is (in this case 8) when you differentiate).

Last edited by Daniel123 (2008-05-02 09:06:11)

casperyc

Member

Registered: 2008-04-30

Posts: 2

Re: Differentiate the following with respect to x

a)    y =  17x³  -  8x²  + 37

dy/dx= 51x^2-16x

                             8
b)    y =  8 (7x  -3)       

dy/dx= 448(7x-3) ^7