Question

Тригонометрия 21 задание,Хелп

Answer 1

3cos5x-3=0
3cos5x=3
cos5x=1
5x=2πn
x=2πn/5,n∈z

Answer 2

$3cos5x-3=0\\cos5x=1\\5x=2pi n,; nin Z\\x=frac{2pi n}{5}; ,; nin Z$