2sin²x+5sinxcosx-3cos²x=0 /cos²x≠0
2tg²x+5tgx-3=0
tgx=a
2a²+5a-3=0
D=25+24=49
a1=(-5-7)/4=-3⇒tgx=-3⇒x=-arctg3+πn
a2=(-5+7)/4=1/2⇒tgx=1/2⇒x=arctg1/2+πn
(x-5)²-x(x-3)=x²-10x+25-x²+3x=25-7x
При x=1,5: 25-7*1,5=25-10,5=14,5
Ответ: 14,5
cosp/4*cosx-sinp/4*sinx = cos(p/4+x)
50+47+44+41+38+35+32+29+26+23+20+17+14+11+8+5+2+(-1)+(-4)+(-7)=430
F(x)=3+8x^2-x^4
D(f)=R
F'(x)=16x-4x^3
D(f)=R
F'(x)=0
16x-4x^3=0
4x(4-x^2)
X=0;x^2=4,x=+ и - (2)
Хmax=-2