Find the derivative of 𝑦 at 𝑥=6,

Answer 1

y' = (7x^6) f'(x) + 42x * f(x)

y'(6) = (7*6^6) * f'(6) + 42*6 * f(6)

= (7*6^6) * -6 + 42*6 * 5

= -1,959,552 + 1260

= -1,958,262

y' = (1/5) [ x * f'(x) + f(x) ]

y'(6) = (1/5) [ 6*-6 + 5]

= (1/5) [ -31) = -31/5