Question

How do you find the instantaneous rate of change of `f (x)= x ^2 +2 x ^4` at `x=1`?

Answer 1

`10" unit/sec."`

Explanation:

We know that, the Instantaneous Rate of Change of `f` at `x=1`

is given by `f'(1)`.

`f(x)=x^2+2x^4 rArr f'(x)=2x+2(4x^3)`.

`:."The Reqd. Rate"=f'(1)=2+8=10" unit/sec."`