%2) 6cos(x)=2x +1
>> x=-2:0.01:2;
>> f1=6*cos(x);
>> f2=2*x+1;
>> figure
>> plot(x,f1,x,f2)
>> grid
>>
>> x=-2:0.01:2;
f1=6*cos(x);
f2=2*x+1;
figure
plot(x,f1,x,f2)
grid
>>
>>
>> x=-5:0.01:4;
f1=6*cos(x);
f2=2*x+1;
figure
plot(x,f1,x,f2)
grid
>> %leikkauspisteet ovat noin -3.4 ja -2.15 ja 1.02
>> %derivaatta
>> syms x
>> diff(6*cos(x)-2*x-1)

ans =

- 6*sin(x) - 2

>> %ratkaisut
>>
>> x=-3.4;
>> delta=100;
>> while(delta>0.000001)
f=6*cos(x)-2*x-1;
Df=-6*sin(x)-2;
X=x-f/Df;
delta=abs(X-x);
x=X;
end
>> x

x =

   -3.4002

>> x=-2.15;
>> delta=100;
>> while(delta>0.000001)
f=6*cos(x)-2*x-1;
Df=-6*sin(x)-2;
X=x-f/Df;
delta=abs(X-x);
x=X;
end
>> x

x =

   -2.1553

>> x=1.02;
>> delta=100;
>> while(delta>0.000001)
f=6*cos(x)-2*x-1;
Df=-6*sin(x)-2;
X=x-f/Df;
delta=abs(X-x);
x=X;
end
>> x

x =

    1.0340

>> %VASTAUS: Ratkaisut ovat -3.4002 ja -2.1553 ja 1.0340