Question

as raizes de equacao de x elevado a dois -7x +12 = 0respectivamente

calcule o log de 14, dado logo 2= 0.3010 e log 7 = 0,8450

calcule a area dos circulos a partir dos raios, dado abaixo considere n= 3,14

Answer 1

x=b^2-4ac

x=(-7)^2 -4.(1).(2)
x=-49-48
x=1

x=-b+/-raiz quadrada de delta/2a
x=-(-7)+/-1/2.1

x'=7+1/2
x'=8/2
x'=4

x"=7-1/2
x"=6/2
x"=3


Log(a.b)=Loga + Logb
Log14= Log2 + Log7
Log14= 0.3010 + 0.8450
Log14= 1.146