Is $g = \{(1, 1), (2, 3), (3, 5), (4, 7)\}$ a function? If $g$ is described by $g(x) = \alpha x + \beta$, then what value should be assigned to $\alpha$ and $\beta$? |
$\alpha = 1, \beta = 0$ $\alpha = 2, \beta = 1$ $\alpha = 2, \beta = -1$ $\alpha = -1, \beta = 2$ |
$\alpha = 2, \beta = -1$ |
The correct answer is Option (3) → $\alpha = 2, \beta = -1$ ## Given that, $g = \{(1, 1), (2, 3), (3, 5), (4, 7)\}$. Here, each element of domain has unique image. So, $g$ is a function. Now given that, $g(x) = \alpha x + \beta$ $g(1) = \alpha + \beta$ $\alpha + \beta = 1$ --- (i) $g(2) = 2\alpha + \beta$ $2\alpha + \beta = 3$ --- (ii) From Eqs. (i) and (ii), we get $2(1 - \beta) + \beta = 3$ $\Rightarrow 2 - 2\beta + \beta = 3$ $\Rightarrow 2 - \beta = 3$ $\beta = -1$ If $\beta = -1$, then $\alpha = 2$ $\alpha = 2, \beta = -1$ |