y'=5^(tgx)ln5*(1/cos^2x)
y''=ln5[cos^2x(5^(tgx)ln5*(1/cos^2x)+5^(tgx)*sin2x)]/cos^4x=
=ln5[5^tgx*ln5+5^tgx*sin2x)/cos^4x=ln5*5^tgx(ln5+sin2x)/cos^4x
y'=5^(tgx)ln5*(1/cos^2x)
y''=ln5[cos^2x(5^(tgx)ln5*(1/cos^2x)+5^(tgx)*sin2x)]/cos^4x=
=ln5[5^tgx*ln5+5^tgx*sin2x)/cos^4x=ln5*5^tgx(ln5+sin2x)/cos^4x