Question

1)0,04^x-6*0,2^x+5=0
2)Sin6x+Cos6x=0

Answer 1

$0.04^x-6cdot0.2^x+5=0\\ 0.2^x=t textgreater 0\ t^2-6t+5=0\ (t-5)(t-1)=0\ t=1\ t=5\\ 0.2^x=1\ 0.2^x=5\\ x=0\ x=log_{0.2}5$

$sin 6x+cos6x = 0\ sin 6x = -cos 6x\ tan 6x = -1\ 6x = -pi/4+pi n\\ x = -frac{pi}{24}+frac{pi n}{6}, quad nin mathbb{Z}$