Question

Alguém pode resolver na formula de delta?
Data a função quadrática y = - x² + 7x - 10 Determine:

Answer 1

y = - x² + 7x - 10
^= - 7² - 4×(-1) × (-10)
^ =49 - 40
^= 9 ~> 3(raiz de delta)
x= - 7±3÷ - 2
x' = 5 x'' = 2
y= -x² + 7x - 10
y= - 5² + 7.5 - 10
y= 25 + 35 - 10
******y' = 50*****
y= - 2² + 7.2 - 10
y = 4 + 14 - 10
*****y'' = 8******

Answer 2

.
$y=- x^{2} +7x-10 \\ \\ - x^{2} +7x-10=0 \\ \\ x^{2} -7x+10=0 \\ \\ a=1 \\ b=-7 \\ c=10 \\ \\ \Delta=b^2-4ac \\ \Delta=(-7)^2-4(1)(10) \\ \Delta=49-40 \\ \Delta=9$

$x=- \frac{b\pm \sqrt{\Delta} }{2a} = \frac{-(-7)\pm \sqrt{9} }{2} = \frac{7\pm3}{2} \\ \\ x'= \frac{7+3}{2} = \frac{10}{2} =5 \\ \\ x"= \frac{7-3}{2} = \frac{4}{2} =2 \\ \\ \\ V=\{2,5\}$