tai x=-1 ta co:
p(x)= 2*(-1)^3 +(-1)+(-1)^2+2=0 suy ra x =-1 la nghiem cua p(x)
tương tự q(x)=0 suy ra x=-1 la nghiem cua q(x)
tai x=-1 ta co:
p(x)= 2*(-1)^3 +(-1)+(-1)^2+2=0 suy ra x =-1 la nghiem cua p(x)
tương tự q(x)=0 suy ra x=-1 la nghiem cua q(x)
a. Xac dinh a de nghiem cua da thuc f(x) = 2x-4 cung la nghiem cua da thuc g(x) = x^2 - ax +2b.
b. Cho f(x) = ax^3 + bx^2 + cx + d, trong do a; b; c; d la hang so va thoa man : b = 3a + c
Chung to rang : f(1) = f(-2)
Bai2: Cho da thuc f(x)=x\(^2\)+4x-5
a, So -5 co phai la nghiem cua f(x) ko?
bViet tap hop S tat ca cac nghiem cua f(x)
Bai 3; Thu gon roi tim nghiem cua cac da thuc sau
a, f(x)=x(1-2x)+(2x\(^2\)-x+4)
b,g(x)=x(x-5)-x(x+2)+7x
c, h(x)=x(x-1)+1
moi nguoi xin hay giup to
Hihihi.Hi moi nguoi.Minh se dat mot cau hoi ve dai so lop 7,mong moi nguoi chi giai><,boi vi toan minh hoc chua gioi lam nen co cac bai toan con thac mac,len day de mong nhan duoc su giup do,de toan nhu sau:(1)Da thuc P(x)=x2016 +2013x + 2012 co ngiem duong khong?Vi sao?. 2 Bai nua nhe(*^-^*):
(2)Cho hai da thuc: M(x)=2,52 -0,5x-x3-1
1/2N(x)=-x3+2,5x2-6+2x
a)Tim A(x)=M(x)-N(x).Sau do tim mot ngiem cua da thuc A(x)
b)Tim da thucB(x) biet B(x)=M(x)+N(x).Cho biet bac cua da thuc B(x).
(3)Cho da thuc:f(x)=ab2 + bx + c.Chung to neu f(x) co ngiem x=-1 thi b=a+c.
MOT BAI NUA THOI MA.NHA NHA NHA MOI NGUOI^_^:
(4)Cho hai da thuc:A=(-1/2axy3)2 va B=(-3a2 x2)3 (a la hang so khac 0).
a)Tinh M=A.B roi cho biet he so va phan bien cua M
b)Tim bac cua M.
AI CO CAU TRA LOI NHAN TIN TRA LOI CHO MINH BIET NHAAAAA.CAM ON!!!!!.
cho da thuc P(x)=x2 + ax + b va Q(x)=x2 + cx + d cho x1;x2 la hai so khac nhau .Chung minh neu P(x) VA Q(x) co cung nghiem la x1;x2 thi P(x)=Q(x)
cho hai da thuc A(x)=2x(x-2)-5(x+3)+7x^3 va B(x)=-x(x+5)-(2x-3)+x(3x^2-2x).a, thu gon A(x),B(x).b, tim nghiem cua da thuc P(x)=A(x)-B(x)-x^2(4x+5)
cho hai da thuc sau:
f(x) = ( x-1) ( x+2) g(x) = x3 + ax2 +bx +2 A) tim nghiem cua f(x) B) xac dinh a va b biet nghiem cua da thuc f(x) cung la nghiem cua da thuc g(x)
cho da thuc f(x) =-6x^3 + 8x^2 -1/2 -4^4 va g(x) = 4x^4+5/2-5x^2+6x^3
tinh h(x)=f(x)+g(x)
chung to h(x) khong co nghiem
a) Xac dinh he so m de da thuc A(x) = mx2_2x co nghiem la 3
b) Chung to da thuc sau khong co nghiem
B(x) = x2+4x+10
Chung minh da thuc Q(x) = x^4 + 3x^2 + 1 khong co nghiem voi moi gia tri cua x