plz answer the above pic
Answers
Answer:
1. solution
Given polynomial f(x)=5x^3 +x^2−5x−1 the factor of g(x)=x+1
If x+1 is factor then x+1=0 or x=−1
Replace x in f(x) by −1 we get
f(x)=5x^3 +x^2−5x−1 g(x)=x+1
f(−1)=5(−1)^3 +(−1)^2−5(−1)−1
⇒f(−1)=−5+1+5−1
⇒f(−1)=0
So f(−1) is zero by g(x)=x+1 then g(x)=x+1 is factor of f(x)=5x^3 +x^2−5x−1
2. solution
Given polynomial f(x)=x^3 +3x^2+3x+1 and g(x)=x+1
If x+1 is factor then f(−1)=0
Replace x in p(x) by −1 we get
f(x)=x^3 +3x ^2+3x+1
or,f(−1)=(−1)^3+3(−1)^2+3(−1)+1
or,f(−1)=−1+3−3+1
or,f(−1)=0
So g(x)=x+1 is factor of f(x)=x^3 +3x^2+3x+1
3. solution
Given polynomial f(x)=x ^3 −4x^ +x+6 the factor of g(x)=x−2
If x-2 is factor then x-2=0 or x=2
Replace x in p(x) by 2 we get
f(x)=x^3−4x^2+x+6
f(2)=(2)^3−4(2)^2 +(2)+6
⇒f(2)=8−16+2+6
⇒f(2)=0
So f(x) is zero by g(x) =x-2 then g(x)=(x-2) is factor of f(x)=x ^3−4x^2 −x+6
4. solution
Given f(x)=3x^3 +x^2−20x+12 the g(x)=3x−2 is the factor
If g(x)=3x−2 is factor then g(x)=3x−2=0 or x=2/3
Replace x by 2/3 in f(x) we get
f(x)=3x^3+x^2 −20x+12
f(2/3 )=3( 2/3)^3+(2/3)^2 −20(2/3)+12
⇒f(2/3 )=3×(8×27) + (4/9)−20×2/3 +12
f(2/3 )=(8/9)+(4/9)- (40/3)+12
f(2/3)= (8+4−120+108)/9= (120−120/9) =0
So f(x)is zero by g(x) then g(x) =3x-2 is factor of f(x)=3x^3+x^2−20x+12
5 solution
Given f(x)=4x^3+20x^2+33x+18 and g(x)=2x+3
Put 2x+3=0
⟹x=−3/2
2x+3 is a factor of f(x) if f(−3/2)=0
replace x by − 3/2 in f(x) we get,
f(−3/2)=4(−3/2)^3+20(− 3/2)^2+33(−3/2)+18
⟹f(−3/2)= −4×(27/8)+20×(9/4)-(99/2)+18
⟹f(−3/2)= − (-54/4)+(180/4)-(99/2)+18
⟹f(−3/2)= (−54+180−198+72) /(4)
⟹f(− )=0
Therefore, g(x) is the factor of f(x)=4x^3+20x ^2+33x+18