<span>log₃ 1/243=log₃ 3⁻⁵=-5log₃ 3=-5</span>
<span>.........................................................................................</span>
5x^2 + 20x = 0
x^2 + 4x = 0
x ( x + 4) = 0
x = 0
x = - 4
// непонятное усвловие
Y`=sinx+xcosx-sinx-3/4cosx=1/4cosx=0
cosx=0⇒x=π/2+πn,n∈z
y(0)=0+1-3/4*0=1наиб
y(π/2)=π/2*1-0-3/4*1=π/2-3/4≈0,82 наим