Question

If f(x) = $\frac{\alpha x}{x + 1}$is continuous then –

• A. a = –1, b = 3
• B. a = 1, b = –3
• C. a = 1, b = 3
• D. a = –1, b = –3

Answer 1

Answer: (A)

a = –1, b = 3

Answer 2

Since the given function is continuous

$- 4 \sin \left( - \frac { \pi } { 2 } \right) + \cos \left( - \frac { \pi } { 2 } \right)$=

⇒ 4 = b – a

and a $\sin \left( \frac { \pi } { 2 } \right)$ + b = $\cos \left( \frac { \pi } { 2 } \right)$ + 2

⇒ a + b = 2 ⇒ a = –1, b = 3