Question

Sabendo que f(x)=3-2x+4x², calcule f'(a).

Answer 1

Derivada de um monômio :

$[\ \text b.\text x^{\text n} \ ]'= \text b.\text n.\text x^{(\text n-1)}$

Temos :

$\text{f(x)}=3-2\text x+4\text x^2$

Derivando :

$\text {f '(x)} = 0-2.1.\text x^{1-1}+4.2.\text x^{2-1} \\\\ \text{f '(x)} = -2 +8\text x$

Fazendo x = a :

$\huge\boxed{\text {f '(a)} = 8.\text a-2\ }\checkmark$