25^cos(3п/2+x)=5^1-cos2x
Корни на отрезке: [-5п; -3п/2]

5^2cos(3π/2+x)=5^1-cos2x2cos(3π/2+x)=1-cos2x2sinx=2sin²x2sin²x-2sinx=02sinx(sinx-1)=0sinx=0⇒x=πn,n∈z-5π≤πn≤-3π/2-5≤n≤-3/2n=-5⇒x=-5πn=-4⇒x=-4πn=-3⇒x=-3πn=-2⇒x=-2πsinx=1⇒x=π/2+2πk,k∈z-5π≤π/2+2πk≤-3π/2-10≤1+4k≤-2-11≤4k≤-3-11/4≤k≤-3/4k=-2⇒x=π/2-4π=--7π/2n=-1⇒x=π/2-2π=-3π/2