You are Here: Home >< Maths

# Homework Help watch

Announcements
1. Can someone help me with these questions?

1) find dy/dx of the following equations:

A) xy = sin^2 (y)
B) tan(2x+y) = x
C) e^(xy) = 4
2. (Original post by Improvement)
Can someone help me with these questions?

1) find dy/dx of the following equations:

A) xy = sin^2 (y)
B) tan(2x+y) = x
C) e^(xy) = 4
Have you studied implicit differentiation? What have you tried so far?
3. I would suggest over viewing implicit differentiation where you differentiate y within the equation, as in not separated on one side. Then apply the respective rules for differentiating.

Alternatively you could try and differentiate with respect to y and see where that takes you.
4. Yeah I completely forgot about that, I have the answer to the first and second one but for the middle one i get sec^2 instead of cos^2?
5. (Original post by Improvement)
Yeah I completely forgot about that, I have the answer to the first and second one but for the middle one i get sec^2 instead of cos^2?
6. (Original post by Improvement)
Can someone help me with these questions?

1) find dy/dx of the following equations:

A) xy = sin^2 (y)
B) tan(2x+y) = x
C) e^(xy) = 4
7. B) gives sec^2(2x+y)*(2+dy/dx)=1 -> 2+dy/dx=1/sec^2(2x+y)=cos^2(2x+y) -> dy/dx = cos^2(2x+y)-2.

(Original post by Improvement)
Yeah I completely forgot about that, I have the answer to the first and second one but for the middle one i get sec^2 instead of cos^2?
8. (Original post by constellarknight)
B) gives sec^2(2x+y)*(2+dy/dx)=1 -> 2+dy/dx=1/sec^2(2x+y)=cos^2(2x+y) -> dy/dx = cos^2(2x+y)-2.
Please don't post full solutions. It's against the rules of the forum and far more beneficial to guide to a solution.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 2, 2016
Today on TSR

### Uni league tables

Do they actually matter?

### University open days

• University of Warwick
Sat, 20 Oct '18
• University of Sheffield
Sat, 20 Oct '18
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 20 Oct '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams