How to find the derivative of this function

In summary: 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.
  • #1
rishi kesh
35
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.
 
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  • #2
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?
 
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  • #3
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 !
 
  • #4
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)
 
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  • #5
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##
 
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  • #6
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.
 
  • #7
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.
 
  • #8
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.
 

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  • #9
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:

1. How do I find the derivative of a basic function?

To find the derivative of a basic function, you can use the power rule, product rule, quotient rule, or chain rule depending on the form of the function. It is important to understand the rules and practice using them to become proficient in finding derivatives.

2. What is the power rule for finding derivatives?

The power rule states that the derivative of a function of the form f(x) = x^n is equal to n*x^(n-1). In other words, you can bring the exponent down in front and decrease the exponent by 1.

3. How do I apply the chain rule to find a derivative?

The chain rule is used when the function is composed of two or more functions. To apply the chain rule, you must take the derivative of the outer function and multiply it by the derivative of the inner function.

4. Can I use the quotient rule to find the derivative of any function?

The quotient rule is used when the function is in the form of f(x) = g(x)/h(x), where g(x) and h(x) are both functions. It cannot be used for all functions, as some may require the use of the power rule or chain rule to find the derivative.

5. How can I check if my derivative is correct?

You can check your derivative by taking the derivative again and seeing if you get back to the original function. This is known as the "reverse chain rule" and can help you confirm that you have found the correct derivative.

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