Question

encontre o zero das funcoes caso existam
a) f(x)=4x-6
b)f(x)=x2-10x+5
c)f(x)=x2-6x+5
d)f(x)=log4x

Answer 1

a) f(x) = 4x-6

4x - 6 = 0
4x = 6
x = 6/4
x = 3/2


b) f(x)= x² -10x + 5

Δ = b² - 4.a.c 
Δ = -102 - 4 . 1 . 5 
Δ = 100 - 4. 1 . 5 
Δ = 80

x = (-b +- √Δ)/2a

x' = (--10 + √80)/2.1
x' = (--10 + √80)/2.1
x' = 18,94427190999916 / 2
x' = 9,47213595499958

x'' = (--10 - √80)/2.1
x'' = 1,0557280900008408 / 2
x'' = 0,5278640450004204


c) f(x)=x² - 6x + 5


Δ = b2 - 4.a.c 
Δ = -62 - 4 . 1 . 5 
Δ = 36 - 4. 1 . 5 
Δ = 16

x = (-b +- √Δ)/2a

x' = (--6 + √16)/2.1  
x' = 10 / 2   
x' = 5   

 x'' = (--6 - √16)/2.1
x'' = 2 / 2
x'' = 1


d) f(x) = log4x


10^x = 4x
x = 0,602059991327962x