Polynomials: 2 marks Questions (CBSE Class 10)
32 different 2 marks questions on Polynomials from CBSE Class 10 Maths board exams 2022–2026, newest first.
If α, β are the zeroes of polynomial p(x) = 6x2−5x−3, then find the value of α1+β1.
Show answer & solution
Answer: −35
- α+β=65, αβ=−63=−21.
- α1+β1=αβα+β=65÷(−21)=−35.
One zero of the polynomial 4x2−12x+(2k+1) is five times the other. Find the value of k.
Show answer & solution
Answer: k = 2
- Let the zeroes be α and 5α.
- Sum: 6α=412=3, so α=21.
- Product: 5α2=42k+1⇒45=42k+1.
- 2k+1=5, so k=2.
If α, β are the zeroes of polynomial p(x) = −9x2−6x+1. Find the value of α2+β2.
Show answer & solution
Answer: 32
- α+β=−−9−6=−32, αβ=−91=−91.
- α2+β2=(α+β)2−2αβ=94+92=32.
Form a quadratic polynomial whose zeroes are twice the zeroes of polynomial p(x) = x2−3x−5.
Show answer & solution
Answer: x2−6x−20
- For x2−3x−5: α+β=3, αβ=−5.
- New zeroes 2α, 2β: sum = 6, product = 4αβ=−20.
- Required polynomial: x2−6x−20 (or any non-zero multiple of it).
Form a quadratic polynomial whose sum and product of the zeroes are 21 and −91 respectively. Hence, find the zeroes of the polynomial.
Show answer & solution
Answer: 18x2−9x−2; zeroes 32 and −61
- Polynomial: x2−(sum)x+product=x2−21x−91, or 18x2−9x−2.
- 18x2−9x−2=18x2−12x+3x−2=6x(3x−2)+1(3x−2)=(6x+1)(3x−2).
- Zeroes: x=32 and x=−61.
If α, β are zeroes of the polynomial x2−6x+7, then find the value of 4(α21+β21).
Show answer & solution
Answer: 4988
- α+β=6, αβ=7.
- α2+β2=(α+β)2−2αβ=36−14=22.
- α21+β21=(αβ)2α2+β2=4922.
- Required value = 4×4922=4988.
If α, β are the zeroes of the polynomial p(x)=x2−3x−1, then find the value of α1+β1.
Show answer & solution
Answer: −3
- α+β=−1−3=3 and αβ=1−1=−1.
- α1+β1=αβα+β=−13=−3.
Find the zeroes of the quadratic polynomial x2+7x+10, and verify the relationship between the zeroes and its coefficients.
Show answer & solution
Answer: Zeroes −2 and −5; relationship verified.
- x2+7x+10=(x+2)(x+5), so the zeroes are −2 and −5.
- Sum of zeroes =−7=−17=−ab.
- Product of zeroes =10=110=ac.
- Hence the relationship is verified.
Find a quadratic polynomial whose zeroes are (5−23) and (5+23).
Show answer & solution
Answer: x2−10x+13
- Sum of zeroes =(5−23)+(5+23)=10.
- Product of zeroes =25−12=13.
- Required polynomial =x2−(sum)x+product=x2−10x+13 (or any non-zero multiple of it).
If α, β are the zeroes of the quadratic polynomial px2+qx+r, then find the value of α3β+β3α.
Show answer & solution
Answer: p3r(q2−2pr)
- α+β=−pq, αβ=pr
- α3β+β3α=αβ(α2+β2)=αβ[(α+β)2−2αβ]
- =pr(p2q2−p2r)=pr⋅p2q2−2pr
- =p3r(q2−2pr)
Find the value of p, for which one zero of the quadratic polynomial px2−14x+8 is 6 times the other.
Show answer & solution
Answer: p = 3
- Let the zeroes be α and 6α.
- Sum: 7α=p14, so α=p2.
- Product: 6α2=p8, so 6×p24=p8.
- p224=p8 gives p = 3.
α and β are the zeroes of the polynomial 5x2−16x−10. Find the value of βα+αβ.
Show answer & solution
Answer: −25178
- α+β=516, αβ=5−10=−2
- α2+β2=(α+β)2−2αβ=25256+4=25356
- βα+αβ=αβα2+β2=25356÷(−2)=−25178
α, β are zeroes of the polynomial p(x)=3x2−6x−5. Find the value of α21+β21.
Show answer & solution
Answer: 2566
- α+β=36=2, αβ=−35
- α2+β2=(α+β)2−2αβ=4+310=322
- α21+β21=(αβ)2α2+β2=322÷925=2566
Find the zeroes of the polynomial p(x)=x2+34x−34.
Show answer & solution
Answer: 32 and −2
- p(x)=31(3x2+4x−4).
- 3x2+4x−4=3x2+6x−2x−4=3x(x+2)−2(x+2)=(3x−2)(x+2).
- p(x)=0 gives x=32 or x=−2.
- Check: sum =32−2=−34 and product =−34, as expected.
If the zeroes of the polynomial x2+ax+b are in the ratio 3:4, then prove that 12a2=49b.
Show answer & solution
Answer: Proved.
- Let the zeroes be 3k and 4k.
- Sum of zeroes: 3k+4k=7k=−a, so k=−7a.
- Product of zeroes: 3k×4k=12k2=b.
- So b=12×49a2, i.e. 49b=12a2.
- Hence 12a2=49b.
If p and q are zeroes of the polynomial p(y)=21y2−y−2, then find the value of (1−p)⋅(1−q).
Show answer & solution
Answer: 76
- p+q=211, pq=21−2
- (1−p)(1−q)=1−(p+q)+pq
- =1−211−212=2118=76
Find a quadratic polynomial whose zeroes are 2 and −57.
Show answer & solution
Answer: 5x2−3x−14 (or any non-zero multiple k(5x2−3x−14))
- Sum of zeroes =2−57=53
- Product of zeroes =2×(−57)=−514
- Polynomial: x2−53x−514, or multiplying by 5, 5x2−3x−14
If 'α' and 'β' are the zeroes of the polynomial p(y)=y2−5y+3, then find the value of α4β3+α3β4.
Show answer & solution
Answer: 135
- α+β=5, αβ=3.
- α4β3+α3β4=α3β3(α+β)=(αβ)3(α+β).
- =33×5=135.
If the sum of the zeroes of the polynomial p(x)=(p+1)x2+(2p+3)x+(3p+4) is −1, then find the value of 'p'.
Show answer & solution
Answer: p=−2
- Sum of zeroes =−p+12p+3=−1.
- 2p+3=p+1, so p=−2.
- Check: p+1=−1=0, so the polynomial is quadratic.
If α and β are zeroes of the polynomial p(x)=x2−2x−1, then find the value of 2α1+2β1+3αβ.
Show answer & solution
Answer: −4
- α+β=2, αβ=−1.
- 2α1+2β1=2αβα+β=−22=−1.
- 3αβ=−3.
- Required value =−1−3=−4.
If α, β are zeroes of the polynomial 8x2+14x+3, then find the value of (α1+β1).
Show answer & solution
Answer: −314
- α+β=−814 and αβ=83.
- α1+β1=αβα+β=3/8−14/8=−314.
Find a quadratic polynomial whose zeroes are −9 and 6.
Show answer & solution
Answer: x2+3x−54 (or any non-zero multiple of it)
- Sum of zeroes =−9+6=−3; product =(−9)(6)=−54.
- Required polynomial =x2−(sum)x+product=x2+3x−54.
If α, β are zeroes of the quadratic polynomial 2x2+7x+5, then find the value of α2+β2+αβ.
Show answer & solution
Answer: 439
- α+β=−27 and αβ=25.
- α2+β2+αβ=(α+β)2−αβ.
- =449−25=449−10=439.
If one zero of the quadratic polynomial 6x2+37x−(p−2) is reciprocal of the other, then find the value of p.
Show answer & solution
Answer: p=−4
- Let the zeroes be α and α1; their product is 1.
- Product of zeroes =ac=6−(p−2).
- 6−(p−2)=1, so p−2=−6.
- p=−4.
If α, β are zeroes of the polynomial p(x)=5x2−6x+1, then find the value of α+β+αβ.
Show answer & solution
Answer: 57
- α+β=−5−6=56 and αβ=51.
- α+β+αβ=56+51=57.
If α and β are zeroes of the quadratic polynomial p(x)=x2−5x+4, then find the value of α1+β1−2αβ.
Show answer & solution
Answer: −427
- α+β=5 and αβ=4.
- α1+β1=αβα+β=45.
- α1+β1−2αβ=45−8=−427.
Find the value of ‘k’ such that the polynomial p(x)=3x2+2kx+x−k−5 has the sum of zeroes equal to half of their product.
Show answer & solution
Answer: k = 1
- p(x)=3x2+(2k+1)x−(k+5)
- Sum of zeroes =−32k+1, product =−3k+5
- Sum = 21 product: −32k+1=−6k+5
- 2(2k+1)=k+5, so 4k+2=k+5
- 3k = 3, k = 1
α,β are the zeroes of the quadratic polynomial p(x)=x2−8x+k, such that α2+β2=40. Find the value of k.
Show answer & solution
Answer: k = 12
- α+β=8 and αβ=k
- α2+β2=(α+β)2−2αβ=64−2k
- 64−2k=40, so 2k = 24 and k = 12
If (−3) is one of the zeroes of the polynomial (k−1)x2+kx+1, find the value of k.
Show answer & solution
Answer: k=34
- Since −3 is a zero, p(−3)=0.
- (k−1)(9)+k(−3)+1=0
- 9k−9−3k+1=0
- 6k=8, so k=34
Find a quadratic polynomial whose zeroes are 6 and −3.
Show answer & solution
Answer: x2−3x−18
- Sum of zeroes =6+(−3)=3; product =6×(−3)=−18.
- Polynomial =x2−(sum)x+product=x2−3x−18 (or any non-zero multiple of it).
Find the zeroes of the polynomial x2+4x−12.
Show answer & solution
Answer: 2 and −6
- x2+4x−12=x2+6x−2x−12=(x+6)(x−2).
- Zeroes: x=2 and x=−6.
If one zero of the polynomial p(x)=6x2+37x−(k−2) is reciprocal of the other, then find the value of k.
Show answer & solution
Answer: k=−4
- Let the zeroes be α and α1; their product is 1.
- Product of zeroes =6−(k−2)
- 6−(k−2)=1⇒k−2=−6⇒k=−4
Practise smarter: chapter-wise revision, formula sheets and step-by-step NCERT solutions on
MonoMath CBSE →