Question

quantas raizes tem a equacao 4^x - 5 . 2^x + 4 = 0 ?​

Answer 1

Resposta:

4^x - 5 . 2^x + 4 = 0

2^(2x) - 5 . 2^x + 4 = 0

faça y=2^x

y²-5y+4=0

y'=[5+√(25-16)]/2=(5+3)/2= 4=2² =2^x  ==>x=2

y'=[5-√(25-16)]/2=(5-3)/2=1 =2^x  ==>x=0

resposta x=0  ou x=2