How to find the derivative of this function

Click For Summary
To find the derivative of the function y = √[(1-sinx)/(1+sinx], basic derivative rules can be applied since the chain rule has not been covered. A suggested approach is to manipulate the expression by multiplying the numerator and denominator by (1-sinx) to simplify the square root. The textbook solution for the derivative is secx(tanx-secx). Utilizing standard derivatives and considering the quotient rule may also aid in solving the problem. Overall, focusing on algebraic manipulation and basic rules can lead to the correct derivative.
rishi kesh
Messages
35
Reaction score
3

Homework Statement


How do we find the derivative of function:
y= √[(1-sinx)/(1+sinx)]
This is the exercise problem from my textbook. I have not covered chain rule yet. So please you basic derivative rules to solve it.

Homework Equations


Here is the answer of derivative given in my textbook: secx(tanx-secx)

The Attempt at a Solution


I have tried replacing square root by power of 1/2 but can't reach to the answer.
 
Physics news on Phys.org
rishi kesh said:

Homework Statement


How do we find the derivative of function:
y= √[(1-sinx)/(1+sinx)]
This is the exercise problem from my textbook. I have not covered chain rule yet. So please you basic derivative rules to solve it.

Homework Equations


Here is the answer of derivative given in my textbook: secx(tanx-secx)

The Attempt at a Solution


I have tried replacing square root by power of 1/2 but can't reach to the answer.

Can you see a way to get rid of the square root?
 
  • Like
Likes rishi kesh
PeroK said:
Can you see a way to get rid of the square root?
Hi! Please give me a little bit of intuition about this. I will solve the rest. Thanks in advance !
 
rishi kesh said:
Hi! Please give me a little bit of intuition about this. I will solve the rest. Thanks in advance !
think of manipulating the terms within the square root itself
(1 - sin^2x = cos ^2x)
 
  • Like
Likes rishi kesh
rishi kesh said:
Hi! Please give me a little bit of intuition about this. I will solve the rest. Thanks in advance !
Whenever you have an expression of the form
##\frac{1+x}{1-x}##

you should think about multiplying top and bottom by ##1+x## or ##1-x##
 
  • Like
Likes rishi kesh
PeroK said:
Whenever you have an expression of the form
##\frac{1+x}{1-x}##

you should think about multiplying top and bottom by ##1+x## or ##1-x##
Hi! I am sorry i tried but i couldn't solve it . I would greatly appreciate your help.
 
rishi kesh said:
Hi! I am sorry i tried but i couldn't solve it . I would greatly appreciate your help.
Multiply top and bottom by ##1-\sin x## and see what comes out.
 
PeroK said:
Multiply top and bottom by ##1-\sin x## and see what comes out.
Here is a picture of what I've solve. Please tell me if its correct.
 

Attachments

  • 1518543915303-2125212252.jpg
    1518543915303-2125212252.jpg
    30.2 KB · Views: 570
rishi kesh said:
Here is a picture of what I've solve. Please tell me if its correct.
Looks good so far. If you can't use the chain rule, you could look for some standard functions that you know the derivative for.

PS I forgot you could use the quotient rule, although I always think of that as the product rule plus the chain rule.
 
Last edited:

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
13
Views
3K
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K