Решить 2 уравнения 1) a)1/tg²x+3/sinx+3=0 b)корни ур-я на [2p;7p/2] 2) a)1/sin²x-1/cos(3p/2-x)=2 b) корни ур-я на [p;5p/2]

1 сos²x/sin²x+3/sinx+3=0 sinx≠0 1-sin²x+3sinx+3sin²x=0 sinx=a 2a²+3a+1=0 D=9-8=1 a1=(-3-1)/4=-1⇒sinx=-1⇒x=-π/2+2πn,n∈z 2π≤-π/2+2πn≤7π/2 4≤-1+4n≤7 5≤4n≤8 5/4≤n≤2 n=2⇒x=-π/2+4π=7π/2 a2=(-3+10/4=-1/2⇒sinx=-1/2 x=-π/6+2πk,k∈z U x=7π/6+2πm,m∈z 2π≤-π/6+2πk≤7π/2 12≤-1+12k≤21 13≤12k≤22 13/12≤k≤11/6 нет решения 2π≤7π/6+2πm≤7π/2 12≤7+12m≤21 5≤12m≤14 5/12≤m≤14/12 m=1⇒x=7π/6+2π=16π/6 2 sinx≠0 2sin²x-sinx-1=0 sinx=a 2a²-a-1=0 D=1+8=9 a1=(1-3)/4=-1/2⇒sinx=-1/2 x=-π/6+2πk,k∈z U x=7π/6+2πm,m∈z π≤-π/6+2πk≤5π/2 6≤-1+12k≤15 7≤12k≤16 7/12≤k≤4/3 k=1⇒x=-π/6+2π=11π/6 π≤7π+2πm≤5π/2 6≤7+12m≤15 -1≤12m≤8 -1/12≤m≤2/3 m=0⇒x=7π/6 a2=(1+3)/4=1⇒sinx=1⇒x=π/2+2πn,n∈z π≤π/2+2πn≤5π/2 2≤1+4n≤5 1≤4n≤4 1/4≤n≤1 n=1⇒x=π/2+2π=5π/2