If x is so small that x3 and higher powers of x may be neglected, then may be approximated as
If both the roots of the quadratic equation x2 – 2kx + k2 + k – 5 = 0 are less than 5, then k lies in the interval
(5, 6]
(6, ∞)
(-∞, 4)
(-∞, 4)
If the equation anxn +an-1xn-1 +....... +a1x =0, a1 ≠ 0, n≥2, has a positive root x = α, then the equation nanxn-1 + (n-1)an-1xn-2 +......+a1 = 0 has a positive root, which is
greater than α
smaller than α
greater than or equal to α
greater than or equal to α
Let z, w be complex numbers such that z iw + = 0 and arg zw = π. Then arg z equals
π/4
5π/4
3π/4
3π/4
If (1 – p) is a root of quadratic equation x2 +px + (1-p)=0 , then its roots are
0, 1
-1, 2
0, -1
0, -1
If one root of the equation x2+px+12 =0 is 4, while the equation x2 +px +q = 0 has equal roots, then the value of 'q' is
49/3
4
3
3
A.
49/3
Since 4 is one of the roots of equation x2 + px + 12 = 0. So it must satisfied the equation.
∴ 16 + 4p + 12 = 0
⇒ 4p = -28
⇒ p = -7
The other equation is x2 - 7x + q = 0 whose roots are equal. Let roots are α and α of above equation
⇒ 2α = 7 ⇒ α = 7/ 2 and product of roots α.α = q ⇒ α2 = q
(7/2)2 = q
q =49/4
The coefficient of xn in expansion of (1+x)(1-x)n is
(n-1)
(-1)n(1-n)
(-1)n-1(n-1)2
(-1)n-1(n-1)2
If 2a + 3b + 6c =0, then at least one root of the equation ax2 + bx+ c = 0 lies in the interval
(0,1)
(1,2)
(2,3)
(2,3)