Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

If c is small in comparison with I, then (II+c)12+(II-C)12 =.


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

2+3c4I

b

2+3c24I2

c

1+3c24I2

d

1+3c4I 

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Here we are given the expression as (II+c)12+(II-C)12  . We need to simplify this expression.
Let us first take I common from the denominator of both terms, we get
 (II+c1)12+(II-c1)12.
Canceling I in the numerator and the denominator of both terms we get
 (II+c1)12+(II-c1)12.
Now using the law of exponents (ab)m= ambm  we get (I)12(I+cI)12+(I)12(I-cI)12.
As we know (I)12=1 so we get  1(I+cI)12+1(I-cI)12. .
We know from the law of exponents that 1a=a-1
 using this we get I+cI-12+(I-cI)-12⋯⋯⋯(1) .
Now let us use the binomial expansion to simplify our answer. Binomial expansion for (1+x)n is given by (1+x)n=1+nx+n(n-1)2!x2+nn-1(n-2)3!x3⋯⋯.
For first term   I+cI-12 we have n=-12 and x=cI  so we get,
I+cI-12=1+-12cI+-12(-12-1)2!cI2+-12-12-1(-12-2)3!cI3+
Simplifying we get,I+cI-12=1−c2I+-12(-32)2!cI2+-12-32(-52)3!cI3+⋯⋯
I+cI-12=1−c2I+38c2I21548c3I3+⋯⋯⋯⋯(2)

For second term  I-cI-12 we have n=-12 and x=-cI so we get,
I-cI-12=1-(-12)( -cI)+ -12(-12-1)2!-cI2+-12-12-1(-12-2)3!-cI3+
Simplifying we get, I-cI-12=1+c2I+-12-322!cI2- -12-32-523!cI3+
 I-cI-12=1+c2I+38c2I2+1548c3I3+⋯⋯⋯⋯(3)
Putting the values from (2) and (3) in (1) we get,
(II+c)12+(II-C)12  =1- c2I++38c2I2 - 1548c3I3+⋯⋯⋯⋯1+c2I+38c2I2+1548c3I3+⋯⋯⋯⋯
Canceling the terms with opposite signs we get,
(II+c)12+(II-C)12=1+38c2I2+1+38c2I2 +…..
2+2×38c2I2+
2+34c2I2+
Now as we are given that c is small in comparison with I, so cI will be small term and c3I3, c4I3 will become very small such that they can be neglected. So ignoring higher powers of cI we have our answer as, (II+c)12+(II-C)12=2+34c2I2
Hence option 2  is the correct answer.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring