Sail E0 Webinar

10th Grade > Mathematics

POLYNOMIALS MCQs

1626393664750aae00754cf

Total Questions : 79 | Page 3 of 8 pages
Question 21. A polynomial y=f(x) when represented on graph cuts xaxis at 2 points and yaxis at 3 points. What is the number of zeroes of f(x) ?
  1.    0
  2.    3
  3.    5
  4.    2
 Discuss Question
Answer: Option D. -> 2
:
D
The zeroes of a polynomial are the points which cuts the xaxis on the graph. As f(x) cuts xaxis at 2 points, the number of zeroes are 2.
Question 22. Which of the following is a polynomial in 1 variable?
  1.    4x + 2
  2.    1(x+1)
  3.    4x + 2 = 0
  4.    x + y
 Discuss Question
Answer: Option A. -> 4x + 2
:
A
A polynomial isa mathematical expression of one or more algebraic terms each of which consists of a constant multiplied withone or more variables raised to a non-negative integral power . For example, (a+bx+cx2) where a, b and c are constants, and x is the variable.
Degree is the highest power of the variable.
4x+2is apolynomialof degree 1.
1(x+1)=(x+1)1, the degree of thisexpression would notbe non-negative. Thus, it is not a polynomial.
4x+2=0 is an equation and hence not a polynomial.
x+y is a polynomial in twovariables, x and y.
Question 23. Which of the following is not a polynomial?
  1.    x+x2
  2.    x+√3
  3.    3√y+y2
  4.    x
 Discuss Question
Answer: Option C. -> 3√y+y2
:
C
All the variables of a polynomialshould have whole numbers asexponents.
Forx+x2,the exponents of thevariable x are 1 and 2. All theexponents are whole numbers.Therefore, it is a polynomial.
In the expression3y+y2,exponentof3yis13,but13is not a wholenumber.Hence,3y+y2is not a polynomial.
Forx+3,the exponent of thevariable is 1which is a whole number.Therefore, it is a polynomial.
For x,the exponentof the variable is1 which is a whole number.Therefore, it is a polynomial.
Question 24. What is the coefficient of z in (z5)3?
  1.    125
  2.    -25
  3.    5
  4.    75
 Discuss Question
Answer: Option D. -> 75
:
D
(z5)3=z3533×z2×5+3×z×52
[Using(ab)3=a3b33a2b+3ab2]
(z5)3 = z312515z2+75z
Hence, the coefficient of z is 75.
Question 25. Which of the following is a zero of (49x21)+(1+7x)2 ?
  1.    −17
  2.    −1
  3.    17
  4.    −1
 Discuss Question
Answer: Option A. -> −17
:
A
Given,(49x21)+(1+7x)2=((7x)212)+(1+7x)2=(7x1)(7x+1)+(1+7x)(1+7x)=(1+7x)(7x1+1+7x)[Taking(1+7x)common]=(1+7x)(14x)
To find the zeroes of a polynomialexpression,we must equate it to zero.(1+7x)(14x)=0(1+7x)=0;(14x)=0x=17,0Zeroes are17&0.
Question 26. If α,β are the zeroes of the polynomial x2px+36 and α2+β2 = 9, then what is the value of p?
  1.    ±6
  2.    ±3
  3.    ±8
  4.    ±9    
 Discuss Question
Answer: Option D. -> ±9    
:
D
Given polynomialx2px+36
On comparing with the standard form of a quadratic polynomial ax2+bx+c, we get
a = 1, b = -p, c = 36
Here, α and β are the zeroes of the polynomial.
α+β=ba=p
and αβ=ca=36
Now, α2+β2=(α+β)2 - 2αβ
9=p22×36 [α2+β2 = 9]
81=p2
p=9or9
Question 27. When 3x3+2x2x+4 is divided by 3+2x the remainder is 18.
  1.    True
  2.    False
  3.    −cd
  4.    −ba
 Discuss Question
Answer: Option A. -> True
:
A
P(x)=3x3+2x2x+4
If P(x) is divided by (xa), then the remainder is P(a)
2x+3=0x=32
So, the remainder is the value of polynomial at 32
Substituting x=32 in p(x)
p(32)=3(32)3+2(32)2(32)+4
p(32)=3(278)+2(94)(32)+4
p(32)=818+92+32+4
p(32)=81+36+12+328
p(32)=81+808
p(32)=18
The remainder is 18.
Thus, the given statement is true.
Question 28. Zeroes of x256x+108 are______.
  1.    both positive
  2.    both negative
  3.    one negative and one positive
  4.    both equal
 Discuss Question
Answer: Option A. -> both positive
:
A
In a quadratic equation ax2+bx+c,both zeroes are positivewhen a is positive, bis negativeand c is positive.
In this case, x256x+108 can be factorized as (x2)(x54).
the roots are 2 and54; both are positive.
Question 29. Graph of a quadratic polynomial is a 
  1.    straight line 
  2.    circle
  3.    parabola
  4.    ellipse
 Discuss Question
Answer: Option C. -> parabola
:
C
Quadratic polynomial is of degree 2 and the graph of a quadratic polynomial is parabola.
Question 30. What will be the remainder when 4x43x3+2x2x is divided by x+1?
  1.    1
  2.    0
  3.    7
  4.    10
 Discuss Question
Answer: Option D. -> 10
:
D
Given p(x)=4x43x3+2x2x
To find the remainder of 4x43x3+2x2xx+1,
we will use remainder theorem.
Remainder of p(x)xa is p(a).
Remainder of4x43x3+2x2xx+1 is p(1).
[x+1=x(1)]
p(1)=4(1)43(1)3+2(1)2(1)
p(1)=4+3+2+1=10
Hence, the remainderof4x43x3+2x2xx+1 is 10.

Latest Videos

Latest Test Papers