1.c1=2-1/3=1 2/3
c2=2-2/3=1 1/3
c3=2-1=1
2.a6= a1+(6-1)d. a6= -40+5*4/5=-40+4=-36
S6=(a1+a6)*6/2=(-40-36)*6/2=-76/2*6=-38*6=-228
3. b4=b1*q^3=2/3*3^3=2/3*27=18
S5=b1(q^5-1)/(q-1)=2/3(3^5-1)\ (3-1)= 2/3(243-1)/2= 2/3*242/2=2/3*121=242/3=80 2/3
<span>z=arctg(x^2+y^2)
z`(x)=1*2x/(1+(x^2+y^2)^2)=</span>2x/(1+x^4+y^4+2x^2y^2)<span>
z`(y)=1*2y/</span>(1+(x^2+y^2)^2)=2y/(1+x^4+y^4+2x^2y^2)
5x-3y+1=0-3
y=-5x-1
<span>y=(-5x-1)/-3</span>
5х²-8х+3=0
а=5,b=-8,c=3
D=(-8)²-4*5*3=64-60=4
8+2 10
x1= _______ = _____ = 1
10 10
8-2 6
x2= _____ =_____ =0.6
10 10
Ответ:1