Yioyjyan

a = -1
b = -0.5
for i = 1:30
c = (a+b)/2
fa = a^4-0.546*a^3-0.226*a^2+0.435*a-0.711
fb =b^4-0.546*b^3-0.226*b^2+0.435*b-0.711
fc = c^4-0.546*c^3-0.226*c^2+0.435*c-0.711
if(fa*fc<0)b=c
end
if(fc*fb<0)a=c
end
a,c,b
end
a =-0.9611
c =
-0.9611
b =
-0.9611
A=0
B=1
for i = 1:30
C=(A+B)/2
fA = (exp(-A)/(1+A^2))-(pi*atan(A)/5)
fB =(exp(-B)/(1+B^2))-(pi*atan(B)/5)
fC = (exp(-C)/(1+C^2))-(pi*atan(C)/5)
if(fA*fC<0)B=C
end
if(fC*fB<0)A=C
end
A,C,BEnd
A =
0.6542
C =
0.6542
B =
0.6542
>> P = [1 -0.546 -0.226 0.436 -0.711]
P =
1.0000 -0.5460 -0.2260 0.4360-0.7110
>> Q = polyder(P)
Q =
4.0000 -1.6380 -0.4520 0.4360
>> polyval(P,pi)
ans =
78.9079
>> x =-1
x =
-1
>> x = x-polyval(P,x)/polyval(Q,x)
x =
-0.9636
>> x = x-polyval(P,x)/polyval(Q,x)
x =-0.9613
>> x = x-polyval(P,x)/polyval(Q,x)
x =
-0.9613
>> x = x-polyval(P,x)/polyval(Q,x)
x =
-0.9613>> x = 1
x =
1
>> x = x-(exp(-x)-(cos(x))^2)/(-exp(-x)+2*cos(x)*sin(x))
x =
0.8597
>> x =x-(exp(-x)-(cos(x))^2)/(-exp(-x)+2*cos(x)*sin(x))
x =
0.8644
>> x = x-(exp(-x)-(cos(x))^2)/(-exp(-x)+2*cos(x)*sin(x))
x =
0.8644