Question

4. Let f(x) = x2 - 81. Find f'(x). (1 point)
O
+ Vx+81
09x
w
1
x2 -81
81

Answer 1

Here we are given that ;

${:\implies \quad \sf f(x)=x^{2}-81}$

Differentiating both sides w.r.t.x ;

${:\implies \quad \sf f^{\prime}(x)=\dfrac{d}{dx}(x^{2}-81)}$

${:\implies \quad \sf f^{\prime}(x)=\dfrac{d}{dx}(x^{2})-\dfrac{d}{dx}(81)}$

${:\implies \quad \sf f^{\prime}(x)=2x^{2-1}-0}$

${:\implies \quad \bf \therefore \quad \underline{\underline{f^{\prime}(x)=2x}}}$

This is the required answer