Advertisements
Advertisements
प्रश्न
Is there any real value of 'a' for which the equation x2 + 2x + (a2 + 1) = 0 has real roots?
Advertisements
उत्तर
Let quadratic equation x2 + 2x + (a2 + 1) = 0has real roots.
Here, a = 1, b = 2 and ,c = (a2 + 1)
As we know that `D = b^2 - 4ac`
Putting the value of a = 1, b = 2 and ,c = (a2 + 1), we get
\[D = \left( 2 \right)^2 - 4 \times 1 \times \left( a^2 + 1 \right)\]
\[ = 4 - 4\left( a^2 + 1 \right)\]
\[ = - 4 a^2\]
The given equation will have equal roots, if D > 0
i.e.
\[- 4 a^2 > 0\]
\[ \Rightarrow a^2 < 0\]
which is not possible, as the square of any number is always positive.
Thus, No, there is no any real value of a for which the given equation has real roots.
APPEARS IN
संबंधित प्रश्न
Solve the following quadratic equations by factorization:
`sqrt2x^2-3x-2sqrt2=0`
Solve the following quadratic equations by factorization:
`x^2-4sqrt2x+6=0`
Solve the following quadratic equations by factorization:
`m/nx^2+n/m=1-2x`
Solve the following quadratic equations by factorization:
x2 - x - a(a + 1) = 0
Solve the following quadratic equations by factorization:
`1/(x-1)-1/(x+5)=6/7` , x ≠ 1, -5
A plane left 40 minutes late due to bad weather and in order to reach its destination, 1600 km away in time, it had to increase its speed by 400 km/hr from its usual speed. Find the usual speed of the plane.
In a class test, the sum of the marks obtained by P in Mathematics and science is 28. Had he got 3 marks more in mathematics and 4 marks less in Science. The product of his marks would have been 180. Find his marks in two subjects.
Solve the following quadratic equations by factorization:
`100/x-100/(x+5)=1`
The sum of natural number and its positive square root is 132. Find the number.
The sum of two natural number is 28 and their product is 192. Find the numbers.
Determine whether the values given against the quadratic equation are the roots of the equation.
x2 + 4x – 5 = 0 , x = 1, –1
Solve the following quadratic equations by factorization: \[\frac{2}{x + 1} + \frac{3}{2(x - 2)} = \frac{23}{5x}; x \neq 0, - 1, 2\]
A two digit number is such that the product of the digits is 14. When 45 is added to the number, then the digit are reversed. Find the number.
The sum of the square of two numbers is 233. If one of the numbers is 3 less than twice the other number. Find the numbers.
Solve equation using factorisation method:
`2x^2 - 1/2x = 0`
An aeroplane travelled a distance of 400 km at an average speed of x km/hr. On the return journey the speed was increased by 40 km/hr. Write down the expression for the time taken for
the return Journey. If the return journey took 30 minutes less than the onward journey write down an equation in x and find its value.
Solve the following quadratic equation by factorisation:
9x2 - 3x - 2 = 0
Solve the following equation by factorization
`(8)/(x + 3) - (3)/(2 - x)` = 2
Solve the following equation by factorization
`sqrt(x(x - 7)) = 3sqrt(2)`
A rectangle of area 105 cm² has its length equal to x cm. Write down its breadth in terms of x. Given that the perimeter is 44 cm, write down an equation in x and solve it to determine the dimensions of the rectangle.
