| Directions: Each of these questions contains two statements: Assertion [A] and Reason [R]. Each of these questions also has four alternative choices, any one of which is the correct answer. You have to select one of the codes [a], [b], [c] and [d] given below. |
| Assertion [A] If \[\alpha \] and \[\beta \]are the zeroes of the polynomial\[{{x}^{2}}+2x-15\], then |
| \[\frac{1}{\alpha }+\frac{1}{\beta }\] is \[\frac{2}{15}\]. |
| Reason [R] If \[\alpha \] and \[\beta \]are the zeroes of a quadratic polynomial \[a{{x}^{2}}+bx+c\], then \[\alpha +\beta =-\frac{b}{a}\] and \[\alpha \beta =\frac{c}{a}\] |
A) A is true, R is true; R is a correct explanation for A.
B) A is true, R is true; R is not a correct explanation for A.
C) A is true; R is False.
D) A is false; R is true.
Correct Answer: A
Solution :
| Let \[f\left( x \right)={{x}^{2}}+2x-15\] |
| \[\alpha +\beta =-2\] and \[\alpha \,.\,\beta =-15\] |
| \[\frac{1}{\alpha }+\frac{1}{\beta }=\frac{\alpha +\beta }{\alpha \,.\,\beta }\] |
| \[=\frac{-2}{-15}=\frac{2}{15}\] |
| Assertion is true. Reason is true. So, Assertion is true, Reason is true; Reason is a correct explanation of Assertion. |
You need to login to perform this action.
You will be redirected in
3 sec
