Doubts

1)Find the value of "t" for which-
e2x= t √x , has only one solution.

2)Let "g" be the inverse function of a differenciable function "f" such that,
G(x) = 1/g(x).
If f(4)=2 & f'(4)= 1/16, then (G'(2))2 =?

3) Value of "a" for which -

ax + sec-12x2-x4 + cosec-12x2-x4 =0 is ?

8 Answers

1
aditya chatterjee ·

is the ans of 2nd prob 1?

13
Avik ·

yes, anakin..

13
Avik ·

Thnx akari [1], But how does it explain tht there exists no other solution ?

19
Debotosh.. ·

does one solution necessarily mean curves touch each other ?

1
akari ·

second one :
g(f(x))=x
g(f(4))=4
g(2)=4
now g'(x)=1/f'(g(x)) ....
see here dude : http://en.wikipedia.org/wiki/Inverse_functions_and_differentiation
now g'(2)=1/f'(g(2))
g'(2)=1/f'(4)
g'(2)=16
now G'(x) = -g'(x)/(g(x))2
G'(2)= -1
G'(2)2=1

1
Ankur Jay ·

First answer is t = 2e12

Second answer is 1. (Both solved by Akari)

For third answer, apply identity directly.

cosec-1 A + sec-1 A = ∩2

Hence for tht qsn, the cosec and sec part becomes pi/2.

Now, we get:

ax + ∩2 = 0.

Hence, a = -∩2x where x belongs to (-∞,1]U[1,∞)

13
Avik ·

Thnx akari n ankur...

Some More :-

An extension to Qn 1) (maybe..)
4) Find the integral values of "t" for which-
e2x= t √x , has exactly 2 distinct solutions.

5) If all the roots of x4-14x2+24x-k=0 are real & distinct, find the possible integral values of "k".

13
Avik ·

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