# Plus 2 - Mathematics Important Questions

Questions 13-19 are provided in this post for practice. If you want more +2 sample one mark questions, refer to the 'Related Post' section below.

13) If $-i + 2$ is one root of the equation $ax^{2}-bx+c=0$, then the other root is

a) $–i - 2$

b) $i - 2$

c) $2 + i$

d) $2i + i$

14) Polynomial equation P(x) = 0 admits conjugate pairs of imaginary roots only if the coefficients are

a) imaginary

b) complex

c) real

d) either real or complex

15) The line $4x+2y=c$ is a tangent to the parabola $y^{2} = 16x$ then c is:

a) -1

b) –2

c) 4

d) -4.

16) The rank of the diagonal matrix

$\begin{bmatrix} -1 & & & & \\ & 2 & & & \\ & & 0 & & \\ & & & -4 & \\ & & & & 0 \\ \end{bmatrix}$ is:

a) 0

b) 2

c) 3

d) 5

17) If A is scalar matrix with scalar k $\neq$, of order 3, then $A^{-1}$is:

a) $\frac{1}{k^2}I$

b) $\frac{1}{k^3}I$

c) $\frac{1}{k}I$

d) $KI$

18) In a system of three linear non-homogenous equations with three unknowns, if $\Delta \; = \; 0$ and $\Delta_{x} \; = \; 0$, $\Delta_{y} \; \neq \; 0$ and $\Delta_{z} \; = \; 0$ then the system has:

a) unique solution

b) two solutions

c) infinitely many solutions

d) no solution.

19) In the system of three linear equations with three unknowns, in the non-homogenous system, $\rho (A) \; = \; \rho (A,B) \;= \; 2$ ; then the system

a) has unique solution

b) reduces to two equations and has infinitely many solutions

c) reduces to a single equation and has infinitely many solutions

d) is inconsistent.

Check here for questions 1-6 and 7-12 .