The Total solution for NCERT class 6-12
If α, β are the zeros of the polynomial f(x) = x2 + x + 1, then
(a) 1(b) -1(c) 0(d) None of these
Answer - 1 : -
If α, β are the zeros of the polynomial p(x) = 4x2 + 3x + 7, then isequal to
Answer - 2 : -
If one zero of the polynomial f(x) = (k2 + 4) x2 + 13x + 4k is reciprocal of the other, thenk =(a) 2(b) -2(c) 1(d) -1
Answer - 3 : - (a)
f (x) = (k2 + 4) x2 + 13x + 4kHere a = k2 + 4, b = 13, c = 4kOne zero is reciprocal of the otherLet first zero = α
If the sum of the zeros of the polynomial f(x) = 2x3 – 3kx2 + 4x – 5 is 6, then value of k is(a) 2(b) 4(c) -2(d) -4
Answer - 4 : - (b)
If α and β are the zeros of the polynomial f(x) = x2 + px + q, then a polynomial having α and β is its zerosis(a) x2 + qx + p(b) x2 – px + q(c) qx2 + px + 1(d) px2 + qx + 1
Answer - 5 : - (c)
If α, β are the zeros of polynomial f(x) = x2 – p (x + 1) – c, then (α + 1) (β + 1) =(a) c – 1(b) 1 – c(c) c(d) 1 + c
Answer - 6 : - (b)
If α, β are the zeros of the polynomial f(x) = x2 – p(x + 1) – c such that (α + 1) (β + 1) = 0, then c =(a) 1(b) 0(c) -1(d) 2
Answer - 7 : - (a)
If f(x) = ax2 + bx + c has no real zeros and a + b + c< 0, then(a) c = 0(b) c > 0(c) c < 0(d) None of these
Answer - 8 : - (d)
f(x) = ax2 + bx + cZeros are not realb2 – 4ac < 0 ….(i)but a + b + c < 0b < – (a + c)Squaring both sides b2 < (a + c)2=> (a + c)2 – 4ac < 0 {From (i)}=> (a – c)2 < 0=> a – c < 0=> a < c
If the diagram in figure shows the graph of the polynomialf(x) = ax2 + bx + c, then(a) a > 0, b < 0 and c > 0(b) a < 0, b < 0 and c < 0(c) a < 0, b > 0 and c > 0(d) a < 0, b > 0 and c < 0
Answer - 9 : - (a)
Curve ax2 + bx + c intersects x-axis at two points andcurve is upward.a > 0, b < 0 and c> 0
Figure shows the graph of the polynomial f(x) = ax2 + bx + c for which(a) a < 0, b > 0 and c > 0(b) a < 0, b < 0 and c > 0(c) a < 0, b < 0 and c < 0(d) a > 0, b > 0 and c < 0
Answer - 10 : - (b)
Curve ax2 + bx + c intersects x-axis at two points andcurve is downward.a < 0, b < 0 and c > 0