FUNCTION, LIMIT AND CONTINUITY

A Function is defined to be rule that associates to may given number x a single number f(x) to be read as function of x. f(x) does not mean f time x. It means given x, the rule f results the number f(x).

Symbolically it may be written in the form y=f(x).

Results

#1. If f(x)=x²-5 evaluate f(3),f(-4),f(5) and f(1)

If f(x)=x²-5 evaluate f(3),f(-4),f(5) and f(1)

f(x)=x²-5

f(3)=3²-5 = 9-5=4

F(-4)=(-4)² -5 =16 -5 =11

F(5)=5²-5=25-5=20

F(1)=1² -5 =1-5 =-4

#2. If f(x)=1-x/1+x then f(f(1/x)) is equal to

If f(x)=1-x/1 x then f(f(1/x)) is equal to

f (1 1-x/1 x)/(1-1-x/1 x)

– 2/2x

-1/x

#3. If g(x) =3 -x² then g(x) is

If g(x) =3 -x² then g(x) is

Answer : An even Function

#4. The value of the limit when n tends to infinity of the expression (7n^3- 8n^2+10n-7)/ (8n^3-9n^2+5) is

The value of the limit when n tends to infinity of the expression (7n^3- 8n^2 10n-7)/ (8n^3-9n^2 5) is

(7*3*2)/(8*3*2)

42/48

answer = 7/8

#5. lim x→∞ [4/x^3+2]

lim x→∞ [4/x^3 2]

lim x→∞(1 1/x)x=e

SO x^3

e=3

#6. The value of the limit of f(x) as x →2 f(x)=e ͯ ³+ 3 ͯ ² +2 ͯ +1

The value of the limit of f(x) as x →2 f(x)=e ͯ ³ 3 ͯ ² 2 ͯ 1

put 2 in x

e^2^3 3^2^2 2^2 1

e^ 8 12 4 1

e ^25

#7. lim x→0 4x+2x-1/x

lim x→0 4x 2x-1/x

a˟-1/x=Logₑ a

Logₑ 4*2

Logₑ 8

#8. lim x →3 = x²-9/x-3

lim x →3 = x²-9/x-3

x²-(3)²/x-3 = na^(n-1)

2(3)^(2-1)

6

#9. lim x →2 2x²-7x +6/5x²-11x+2 is equal to

lim x →2 2x²-7x 6/5x²-11x 2 is equal to

(2x-3)(x-1)/(5x-1)(x-2)…….put x→2

1/9

 

 

#10. If f(x) =2x²+6x-5/12x²+x-20 is to be discontinuous then

If f(x) =2x² 6x-5/12x² x-20 is to be discontinuous then

answer  x=  5/4

#11. lim x→0 log (1+7*x/3)/x

lim x→0 log (1 7*x/3)/x

lim x→0 log(1 x)/x=1

log (1 7x/3)/7x/3*3/7

log 7/3

#12. lim x→0 (1+5x)^1/x

lim x→0 (1 5x)^1/x

By rule lim x→0 (1 x)^1/x=e

(1 5x)^1/5x*5

e^5

#13. The value of the limit when x tends to zero of the expression (1+n)^1/n is

(1 n)^1/n is

By rule lim tends to x is 0 (1 x)^1/x÷x = e

Answer= e

#14. Evaluate lim x tends to 2 x²+2x-1/√x²+2

lim x-> 2  x² 2x-1/√x² 2

lim x-> 2 (x² 2x-1)/lim x-> 2√x² 2

lim x-> 2 x² lim x-> 2x-1/lim x-> 2√x² 2

(2)² 2*2-1/√(2)² 2

7/√6

#15. lim x→0 x/log(1+x) is equal to

lim x→0 x/log(1 x) is equal to

By Limit rule

Answer is 1

#16. Lim x→0 (x+6/x+1)^x+4

Lim x→0 (x 6/x 1)^x 4

By using Limit rule

=limx0(1 5x 1)(x 4)

limx0(1 5)^x

e^5

#17. 3x^2 + 2x -1 is continuous

3x^2 2x -1 is continuous

Answer At x=2 & For every value of x

#18. Lim x->2 (x^2-5/x-4)

Lim x->2 (x^2-5/x-4)

2(2)^2-5/2-4

8-5/-2

=-3/4

#19. lim n-> 2 x^5-32/x-2

lim n->2  x^5-32/x-2

lim n->2 x^5 -(2)^5/x-2

5(2)^(5-1)

5*16

=80

#20. Lim x→0 sin(5x/x)

Lim x→0 sin(5x/x)

Lim x→0 sin(5x)/5x*1/x)

1/¹/₅

5

Finish

Leave a Comment

Your email address will not be published. Required fields are marked *