Question

Os zeros da função f(x) = -x² + 4x - 3 são:

Answer 1

$f(x)=- x^{2} +4x-3 \\\\ a=-1;b=4;c=-3\\ \\ \Delta =b^{2} -4.a.c \to \Delta= 4^{2} -4.(-1).(-3) \to \Delta=16-12\to \Delta=4 \\ \\x= \frac{-b+- \sqrt{\Delta} }{2.a} \to x= \frac{-4+- \sqrt{4} }{2.(-1)} \to x= \frac{-4+- 2 }{-2} \\ \\x'= \frac{-4+ 2 }{-2}\to x'= \frac{2 }{-2}\to x'=-1 \\\\ x''= \frac{-4- 2 }{-2}\to x''= \frac{-6}{-2}\to x''=3 \\\\\\ S=(-1,3)$

R: Os zeros são (-1,3).