Question

If ƒ(x ) = 3x + 1, then ƒ(a + h ) - ƒ(a ) =

Answer 1

Hello,

f(a+h)=3(a+h)+1=3a+3h+1
f(a)=3a+1
f(a+h)-f(a)=3a+3h+1-(3a+1)=3h

`\lim_(h \to 0) (f(a+h)-f(a))/(h)=\lim_(h \to 0)(3h))/(h)=3`

f'(x)=3