Sail E0 Webinar

10th Grade > Mathematics

POLYNOMIALS MCQs

1626393664750aae00754cf

Total Questions : 79 | Page 2 of 8 pages
Question 11. Find the zeros of the quadratic polynomial x28x+12.
  1.    2 and 6
  2.    8 and 4
  3.    10 and 2
  4.    4 and 5
 Discuss Question
Answer: Option A. -> 2 and 6
:
A
To find the zeroes, equate the polynomial to zero and then factorise.
x28x+12=0
x26x2x+12=0
x(x6)2(x6)=0
(x6)(x2)=0
x6=0orx2=0x=6;2
2and6are the zeros of the quadraticpolynomial.
Question 12. Find the quadratic polynomial whose zeroes are 6+33 and 633 .
  1.    x2−16x+9
  2.    3x2−12x+11
  3.    6x2−4x+1
  4.    7x2−4x+11
 Discuss Question
Answer: Option B. -> 3x2−12x+11
:
B
Letα&β be the roots.
Sum of zeroes, α+β=6+33+633 =123=4
Product of zeroes, αβ=6+33×633=62(3)29αβ=3639=339=113
Required polynomial f(x)=[(x2(α+β)x+(αβ)]=[(x24x+113]
Multiplying by 3
f(x)=3x212x+11
the required polynomial is 3x212x+11.
Question 13. Priya lost her homework paper on polynomials and she doesn't remember the divisor which, on dividing the polynomial x33x2+x+2 gives quotient (x2) and remainder (2x+4). Find the divisor.
 
  1.    5x2−7x+9
  2.    x2−8x+7
  3.    x2−x+1
  4.    6x2−x+11
 Discuss Question
Answer: Option C. -> x2−x+1
:
C
We know that,
Dividend = Divisor x Quotient +Remainder
x33x2+x+2=Divisor×(x2)+(2x+4)
Divisor×(x2)=x33x2+x+2+2x4
Divisor=(x33x2+3x2)x2
Priya Lost Her Homework Paper On Polynomials And She Doesn't...
Divisor=x2x+1
Question 14. When a polynomial is divided by (x+2), the quotient and remainder are (2x-1) and 3 respectively. Find the polynomial.
  1.    2x2+6x+11
  2.    5x2+3x+8
  3.    6x2+3x+9
  4.    2x2+3x+1
 Discuss Question
Answer: Option D. -> 2x2+3x+1
:
D
We know that, by divison algorithm,
Dividend = Divisor x Quotient + Remainder.
P(x)=(x+2)×(2x1)+3=x(2x1)+2(2x1)+3=2x2x+4x2+3P(x)=2x2+3x+1
The required polynomialis2x2+3x+1.
Question 15. Find the zeroes of the polynomial x22.
 
  1.    √2 and −√5
  2.    4 and 3
  3.    √2 and −√2
  4.    −5 and 2 
 Discuss Question
Answer: Option C. -> √2 and −√2
:
C
To find the zeroes, equate the givenpolynomial to zero.
x22=0
Using the identity,a2b2=(a+b)(ab)
(x+2)(x2)=0
x+2=0andx2=0
x=2andx=2
Hence, the zeroes are2,2.
Question 16. Find the quadratic polynomial whose sum of its zeroes (roots) is 85 and the product of the zeroes (roots)  is 75.
  1.    14x2+7x+5
  2.    5x2+8x+7
  3.    2x2−8x+7
  4.    5x2−8x+7
 Discuss Question
Answer: Option B. -> 5x2+8x+7
:
B
Given that,
Sum of zeroes =85
Product of zeroes =75
Required quadratic polynomial is,
f(x)=[(x2(sumofroots)x+(productofroots)]
Substituting the given values we get,
f(x)=[x2(8)5x+75]
f(x)=[x2+85x+75]
multiplying by 5 we get
f(x)=5x2+8x+7
Required polynomial is 5x2+8x+7.
Question 17. The product of zeros of cubic polynomial x33x2x+3 is 
  1.    -3
  2.    -1
  3.    3
  4.    1
 Discuss Question
Answer: Option A. -> -3
:
A
For a cubic polynomial ax3+bx2+cx+d
Sum of zeros = ba
Product of zeros =da
Product of zeros is31 = -3
Question 18. If α,β and γ are the zeroes of the cubic polynomial ax3+bx2+cx+d,
then α+β+γ is equal to
  1.    ca
  2.    -da
  3.    cd
  4.    -ba
 Discuss Question
Answer: Option D. -> -ba
:
D
Ifα,β and γare the zeroes of thecubic polynomialax3+bx2+cx+d, then
sum of its zeroes
= α+β+γ
=(coefficientofx2)(coefficientofx3)=ba
Question 19. If p(x)=x233x+1, then the value of p(33) is 0.
  1.    True
  2.    False
  3.    3√y+y2
  4.    x
 Discuss Question
Answer: Option B. -> False
:
B
Given,p(x)=x233x+1x=33
p(33)=(33)233(33)+1p(33)=2727+1p(33)=0+1=1
Thus, the given statement is false.
Question 20. What is the remainder when 3x27x+5 is divided by (x1) ?
  1.    0
  2.    1
  3.    2
  4.    3
 Discuss Question
Answer: Option B. -> 1
:
B
Given f(x) =3x27x+5
To find the remainderwhen it is divided by (x1), we useremainder theorem.
Remainder of f(x)(xa) is f(a).
f(1)=37+5=1
The remainder when 3x27x+5 is divided by (x1) is 1.

Latest Videos

Latest Test Papers