1)5cos2x-3sin2x=05сos²x-5sin²x-6sinxcosx=0/-cos²x≠05tg²x+6tgx-5=0tgx=a5a²+6a-5=0D=36+100=136a1=(-6-2√34)/10=-0,6-0,2√34⇒tgx=-0,6-0,2√34⇒x=-arctg(0,6+0,2√34)+πna2=-0,6+0,2√34⇒tgx=0,2√34-0,6⇒x=arctg(0,2√34-0,6)+πn2)cos^2x-3sin^2x=0(1+cos4x)/2-3(1-cos4x)/2=01+cos4x-3+3cos4x=04cos4x=2⇒cos4x=1/2⇒4x=+-π/3+2πn⇒x=+-π/12+πn/23)3sin^2x-4sinx*cosx+5cos^2x=23sin^2x-4sinx*cosx+5cos^2x-2sin²x-2cos²x=0sin²x-4sinxcosx+3cos²x=0 /cos²x≠0tg²x-4tgx+3=0tgx=aa²-4a+3=0⇒a1+a2=4 U a1*a2=3a1=1⇒tgx=1⇒x=π/4+πna2=3⇒tgx=3⇒x=arctg3+πn4)sin^4x-cos^4x=sin2x(sin²x-cos²x)(sin²x+cos²x)=sin2xsin²x-cos²x-2sinxcosx=0 /cos²x≠0tg²x-2tgx-1=0tgx=aa²-2a-1=0D=4+4=8a1=(2-2√2)/2=1-√2⇒tgx=1-√2⇒x=arctg(1-√2)+πna2=1+√2⇒tgx=1+√2⇒x=arctg(1+√2)+πn5)2sin^2x-cos(pi/2+x)sin(3/2pi+x)-sin^2(3pi/2+x)=4arccos1 2sin²x-(-sinx)*(-cosx)-cos²x=4*02sin²x-sinxcosx-cos²x=0/cos²x≠02tg²x-tgx-1=0tgx=a2a²-a-1=0D=1+8=9a1=(1-3)/4=-1/2⇒tgx=-1/2⇒x=-arctg1/2+πna2=(1+3)/4=1⇒tgx=1⇒x=π/4+πn