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Prove that the function f (x) = 5x – 3 is continuous at x = 0, at x = – 3 and at x = 5. - Mathematics

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Question

Prove that the function f (x) = 5x – 3 is continuous at x = 0, at x = – 3 and at x = 5.

Sum

Solution

The given function is:

f(x) = 5x - 3

f(0) = 5(0) - 3 = -3

`lim_(x → 0) f(x) = 5(0) - 3 = -3`

`lim_(x → 0) f(x) = f(0)`

Hence, the function is continuous at x = 0

f(-3) = 5(-3) - 3

= -15 - 3

= -18

⇒ `lim_(x → -3) f(x) = 5(-3) - 3`

= -15 - 3

= -18

⇒ `lim_(x → -3) f(x) = f(-3)`

Hence , function is continous at x = -3

f(5) = 5(5) - 3

= 25 - 3

= 22

⇒ `lim_(x → 5) f(x) `

= 5(5) - 3

= 25 - 3

= -22

⇒ `lim_(x → 5) f(x) = f(5)`

Hence , function is continuous at x = 5

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Chapter 5: Continuity and Differentiability - Exercise 5.1 [Page 159]

APPEARS IN

NCERT Mathematics [English] Class 12
Chapter 5 Continuity and Differentiability
Exercise 5.1 | Q 1 | Page 159

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