Question

найти нули функции у=cosх/2
найти нули функции у=sin 3x

Answer 1

$y=cosfrac{x}{2} \ left { {{x=0} atop {y=cos0}} right. left { {{x=0} atop {y=1}} right. \ left { {{cosfrac{x}{2}=0} atop {y=0}} right. left { {{frac{x}{2}=frac{pi}{2}+pi n, nin Z atop {y=0}} right. left { {{x=pi+2pi n, nin Z} atop {y=0}} right. \OTBET: {(0;1);(pi+2pi n;0)}, nin Z$
$\y=sin3x \ left { {{x=0} atop {y=sin0}} right. left { {{x=0} atop {y=0}} right. \ left { {{sin3x=0} atop {y=0}} right. left { {{3x=pi n, nin Z} atop {y=0}} right. left { {{x=frac{pi n}{3}, nin Z} atop {y=0}} right. \OTBET:(frac{pi n}{3};0), nin Z$