Question

dada a funçao f(x)= x² - 5x + 4 calcule: f(-2), f(1sobre2), f(0)+f(4)

Answer 1

$f(x)= x^{2} -5x+4\\\\\\f(-2)\to (-2) ^{2} -5.(-2)+4\to 4+20+4\to 28\\\\f( \frac{1}{2})\to ( \frac{1}{2})^{2} -5.( \frac{1}{2})+4\to \frac{1}{4} - \frac{5}{2} +4\to - \frac{4}{2} +4\to -2+4\to 2\\\\f(0)\to 0^{2} -5.0+4\to 0-0+4\to 4\\\\f(4)\to 4^{2} -5.4+4\to 16-20+4\to 20-20\to 0$