Question

y= 1/ (7x-8)^5 find dxy

Answer 1

y = (7x-8)^-5...use the power rule...
y' = -5/((7x-8)^6)

Answer 2

answer on the book is -35/ (7x-8)^6 ?

Answer 3

yes, sorry...chain rule...so multiply my answer above by derivative of 7x-8...so that gives -35/(7x-8)^6...

Answer 4

can you explain how to do chain rule on this to get the answer?

Answer 5

yes. first use the power rule by bringing down -5 and subtracting 1 from -5 giving the new exponent...
-5(7x-8)^-6...then multiply that by the derivative of (7x-8)...
-5(7x-8)^-6 * 7...
-35(7x-8)^-6...
-35/(7x-8)^6

Answer 6

thank you very much.. your awsome