ANSWER :
The answer is :
[tex]\frac{f(a+h)-f(a)}{h}=-2a-h[/tex]EXPLANATION :
From the problem, we have the function :
[tex]f(x)=1-x^2[/tex]We need to find f(a + h) and f(a).
That will be :
[tex]\begin{gathered} f(a+h)=1-(a+h)^2 \\ =1-a^2-2ah-h^2 \\ \\ f(a)=1-a^2 \end{gathered}[/tex]Then plug in to the required functions :
[tex]\begin{gathered} \frac{f(a+h)-f(a)}{h}=\frac{(1-a^2-2ah-h^2)-(1-a^2)}{h} \\ =\frac{-2ah-h^2}{h} \\ =-2a-h \end{gathered}[/tex]