# Recent questions tagged quadratic-equations 1 vote
1
Suppose one of the roots of the equation $ax^{2} – bx + c = 0$ is $2 + \sqrt{3},$ where $a, b$ and $c$ are rational numbers and $a \neq 0.$ If $b = c^{3}$ then $|a|$ equals $2$ $4$ $1$ $3$
1 vote
2
A person buys tea of three different qualities at $₹ \; 800, ₹ \; 500,$ and $₹ \; 300 \; \text{per kg},$ respectively, and the amounts bought are in the proportion $2:3:5.$ She mixes all the tea and sells one-sixth of the mixture at $₹ \; 700 \; \text{per kg}.$ The ... $\text{INR per kg},$ at which she should sell the remaining tea, to make an overall profit of $50 \%,$ is $675$ $653$ $692$ $688$
1 vote
3
Let $\text{m}$ and $\text{n}$ be positive integers, If $x^{2} + mx + 2n = 0$ and $x^{2} + 2nx + m = 0$ have real roots, then the smallest possible value of $m + n$ is $7$ $8$ $5$ $6$
4
In how many ways can a pair of integers $\textsf{(x , a)}$ be chosen such that $x^{2} – 2 |x| + |a-2| = 0 ?$ $4$ $5$ $6$ $7$
1 vote
5
If $x= \frac{\sqrt{p^{2}+q^{2}}+\sqrt{p^{2}-q^{2}}}{{\sqrt{p^{2}+q^{2}}-\sqrt{p^{2}-q^{2}}}}$ then $q^{2}x^{2}-2p^{2}x+q^{2}$ equals to : $3$ $-1$ $-2$ $0$
6
The expression $(11.98\times 11.98 + 11.98 \times x +0.02 \times 0.02)$ will be a perfect square for $x$ equal to: $2.02$ $0.17$ $0.04$ $1.4$
7
sum of roots of the equation $\dfrac{3x^{3}-x^{2}+x-1}{3x^{3}-x^{2}-x+1}=\dfrac{4x^{3}-7x^{2}+x+1}{4x^{3}+7x^{2}-x-1}$ is : $0$ $1$ $-1$ $2$
8
If ${m_1}$ and ${m_2}$ are the roots of equation $x^{2}+(\sqrt{3}+2)x+\sqrt{3}-1=0$ then area of the triangle formed by the lines $y={m_1}x, \: \: y={m_2}x, \: \: y=c$ is: $\bigg(\dfrac{\sqrt{33}+\sqrt{11}}{4}\bigg) c^{2}$ $\bigg( \dfrac{\sqrt{32}+\sqrt{11}}{16}\bigg ) c$ $\bigg (\dfrac{\sqrt{33}+\sqrt{10}}{4} \bigg ) c^{2}$ $\bigg( \dfrac{\sqrt{33}+\sqrt{21}}{4} \bigg) c^{3}$
9
Vidya and Vandana solved a quadratic equation. In solving it, Vidya made a mistake in the constant term and got the roots as $6$ and $2$, while Vandana made a mistake in the coefficient of $x$ only and obtained the root as $-7$ and $-1$. The correct roots of the equation are: $6,-1$ $-7,2$ $-6,-2$ $7,1$
1 vote
10
The quadratic equation $x^{2}+bx+c=0$ has two roots $4a$ and $3a$, where a is an integer. Which of the following is a possible value of $b^{2}+c$? $3721$ $549$ $427$ $361$
1 vote
11
Let $A$ be a real number. Then the roots of the equation $x^{2}-4x-\log _{2}A=0$ are real and distinct if and only if $A> \frac{1}{16}$ $A> \frac{1}{8}$ $A< \frac{1}{16}$ $A< \frac{1}{8}$
12
If $a$ and $b$ are integers such that $2x^{2}- ax + 2 > 0$ and $x^{2}-bx+8 \geq 0$ for all real numbers $x$, then the largest possible value of $2a-6b$ is _________
1 vote
13
The minimum possible value of the sum of the squares of the roots of the equation $x^{2}+\left ( a+3 \right )x-\left ( a+5 \right )=0$ is $1$ $2$ $3$ $4$
1 vote
14
If $f_{1}\left ( x \right )=x^{2}+11x+n$ and $f_{2}\left ( x \right )=x$, then the largest positive integer $n$ for which the equation $f_{1}\left ( x \right )=f_{2}\left ( x \right )$ has two distinct real roots, is $24$ $23$ $19$ $10$
1 vote
15
Given the quadratic equation $x^2 – (\text{A} – 3)x – (\text{A} – 2)$, for what value of $\text{A}$ will the sum of the squares of the roots be zero? $-2$ $3$ $6$ $\text{None of these}$
16
If both $a$ and $b$ belong to the set $\{1,2,3,4\}$, then the number of equations of the form $ax^2+bx+1=0$ having real roots is _______
17
If $ax^{2}+bx+c= 0$ and $2a,b$ and $2c$ are in arithmetic progression, which of the following are the roots of the equation? $a,c \\$ $-a,-c \\$ $-\dfrac{a}{2},-\dfrac{c}{2} \\$ $-\dfrac{c}{a},-1$
18
If $\alpha$ and $\beta$ are the roots of the quadratic equation $x^{2}-10x+15= 0$, then find the quadratic equation whose roots are $\bigg(\alpha+\dfrac{\alpha }{\beta }\bigg)$ and $\bigg(\beta +\dfrac{\beta}{\alpha}\bigg)$ $15x^{2}+71x+210= 0$ $5x^{2}-22x+56= 0$ $3x^{2}-44x+78= 0$ Cannot be determined
19
If the roots of the equation $(a^{2}+b^{2})x^{2}+2(b^{2}+c^{2})x+(b^{2}+c^{2})= 0$ are real, which of the following must hold true? $c^{2}\geq a^{2}$ $c^{4}\geq a^{2}(b^{2}+c^{2})$ $b^{2}\geq a^{2}$ $a^{4}\leq b^{2}(a^{2}+c^{2})$
1 vote
20
For which value of $k$ does the following pair of equations yield a unique solution for $x$ such that the solution is positive? $x^{2}-y^{2}=0$ $(x-k)^{2}+y^{2}=1$ $2$ $0$ $\sqrt{2}$ $\sqrt{-2}$
21
If one root of $x^{2} + px + 12 = 0$ is $4$, while the equation $x^{2} + px + q = 0$ has equal roots, then the value of $q$ is: $49/4$ $4/49$ $4$ $\frac{1}{4}$
1 vote
22
One root of $x^{2} + kx – 8 = 0$ is square of the other. Then, the value of k is: $2$ $8$ $-8$ $-2$
–1 vote
23
Given the quadratic equation $x^{2}-(A-3) x- (A-2) = 0$, for what value of $A$ will the sum of the squares of the roots be zero? $-2$ $3$ $6$ None of these
24
If both $a$ and $b$ belong to the set $\{1, 2, 3, 4\}$, then the number of equations of the form $ax^2 + bx + 1 = 0$ having real roots is $10$ $7$ $6$ $12$
25
Choose $1$ if the question can be answered by one of the statements alone but not by the other. Choose $2$ if the question can be answered by using either statement alone. Choose $3$ if the question can be answered by using both the statements together, but cannot be answered by using either statement ... $-3 \leq a \leq 3$ One of the roots of the equation $4x^2 - 4x +1 =0$ is $a.$
26
Choose $1$ if the question can be answered by one of the statements alone but not by the other. Choose $2$ if the question can be answered by using either statement alone. Choose $3$ if the question can be answered by using both the statements together, but cannot be answered by using either statement ... $\frac{1}{2}$ the ratio of $c$ and $b$ is $1.$
27
Let $f(x) = ax^2 + bx +c$, where $a, b$ and $c$ are certain constants and $a \neq 0$. It is known that $f(5) = -3 f(2)$ and that $3$ is a root of $f(x)=0$. What is the value of $a+b+c?$ $9$ $14$ $13$ $37$ cannot be determined
28
Ujakar and Keshab attempted to solve a quadratic equation. Ujakar made a mistake in writing down the constant term. He ended up with the roots $(4, 3).$ Keshab made a mistake in writing down the coefficient of $x.$ He got the root as $(3, 2).$ What will be the exact roots of the original quadratic equation? $(6, 1)$ $(–3, –4)$ $(4, 3)$ $(–4, –3)$
29
The number of roots of $\frac{A^2}{x} + \frac{b^2}{x-1} =1$ is $1$ $2$ $3$ None of these
30
Let $p$ and $q$ be the roots of the quadratic equation $x^2 - (a-2) x-a -1 =0.$ What is the minimum possible value of $p^2 + q^2?$ $0$ $3$ $4$ $5$
31
Let $f(x) = ax^2 - b |x|$, where $a$ and $b$ are constants. Then at $x=0, f(x)$ is, maximized whenever $a>0, b>0$ maximized whenever $a>0, b<0$ minimized whenever $a>0, b>0$ minimized whenever $a>0, b<0$
For which value of $k$ does the following pair of equations yield a unique solution for $x$ such that the solution is positive? $x^2 - y^2 =0$ $(x-k)^2 + y^2 =1$ $2$ $0$ $\sqrt{2}$ -$\sqrt{2}$
A quadratic function f(x) attains a maximum of $3$ at $x=1.$ The value of the function at $x=0$ is $1.$ What is the value of $f(x)$ at $x=10?$ $-119$ $-159$ $-110$ $-180$ $-105$
Let $f(x) = ax^2 + bx +c$, where $a$, $b$ and $c$ are certain constants and $a \neq 0$. It is known that $f(5) = -3 f(2)$ and that 3 is a root of $f(x)=0$. What is the other root of $f(x)=0?$ $-7$ $-4$ $2$ $6$ cannot be determined