If ƒ(x ) = 3x + 1, then ƒ(a + h ) - ƒ(a ) =
Hello,f(a+h)=3(a+h)+1=3a+3h+1f(a)=3a+1f(a+h)-f(a)=3a+3h+1-(3a+1)=3h\(\lim_{h \to 0} \frac{f(a+h)-f(a)}{h}=\lim_{h \to 0}\frac{3h)}{h}=3\)f'(x)=3
